From the second scene starting at 0:03 and ending at 0:06, WFT does a Nair, Utilt, Ftilt, and Uair.
Nair hits Little Mac on frame 11, the frame that WFT touches her knees and the frame before the second hit. I would assume it's the same in startup as in Smash 4 as according to the SSBwiki's hitbox viewer, the first active frame, frame 9, should appear when WFT's body is parallel to the ground:
https://www.ssbwiki.com/Wii_Fit_Trainer_(SSB4)/Neutral_aerial. The same frame of animation appears on frame 9 in the video and with Little Mac getting hit on frame 11, that also means the first hit is still frames 9-11, 3 active frames while the second hit is frame 12 and probably 2 active frames as well, last active frame being 13.
Nair's landing lag is 9 frames down from 14 in Smash 4. The starting frame is when WFT touches the ground indicated by WFT suddenly shifting from Nair's animation to landing in a crouched position and the puffs of dust, smoke, whatever they are that appears around WFT and everyone else when they land. From there, WFT stays in a landing animation for 9 frames before she begins Utilt on frame 10 which is indicated by WFT crouching down lower and turning her body to look up. If WFT's auto-cancel window is the same or similar to in Smash 4, I think Nair could have been auto-canceled, but it looks like WFT used Nair just as she was falling.
Utilt is still frame 5. The starting frame is when WFT suddenly shifts from Nair's landing animation to looking towards the screen as WFT is about to look up for Utilt. From there, Little Mac gets hit on frame 5.
If Utilt didn't hit anyone, it would be easy to obtain its total frames since there wouldn't be any hit lag to factor in. That said, WFT and Little Mac experience 13 frames of hit lag, including the frame Utilt hit Little Mac, before Little Mac starts to get launched. If those 13 frames are ignored and treated as the next frame of Utilt's animation, then Utilt has 29 total frames as WFT begins her Ftilt on frame 30, Utilt's FAF; FAF is total frames +1. That is 5 less total frames than in Smash 4 which had 34 total frames. If Utilt has the same 3 active frames with it last active frame being 7, then Utilt has 23 recovery frames down from Smash 4's 28. Recovery frames is FAF minus last active frames for non-projectiles, so 30 FAF - 7 last active frame = 23 recovery frames.
Ftilt I believe is still frame 6, but as it hit Little Mac on frame 10, it appears that its active frames were increased by at least 3 frames. For the startup, the starting frame is when WFT suddenly shifts from the recovery animation for Utilt to standing straight up with her left knee up. On frame 6, WFT enters into Ftilt's hit pose, but Little Mac doesn't get hit until frame 10. In Smash 4, Ftilt was frames 6-7, 2 active frames. In Ultimate, Ftilt is at least frames 6-10, 5 active frames. I'm not sure if it's active for longer as that'll have to wait until the game's released and we can get a datamine for Ultimate or WFT ends up being playable for a demo build in the future and someone gets Ftilt to on frames +11.
So, the same deal with its total frames where if it didn't hit anyone, it'd be easier to obtain. Here, WFT and Little Mac experience 12 frames of hit lag before Little Mac starts to get launched. If those are ignored and treated as the next frame of Ftilt's animation, then Ftilt has the same 32 total frames as in Smash 4. WFT begins to jump on frame 33, its FAF. Because of its higher active frames, Ftilt's recovery did decrease, but its commitment, 32 total frames, remains the same. As we don't know the exact frames its active for, we can only estimate its recovery frames which is at most 23 recovery frames. 33 FAF - 10 last active frame = 23 recovery frames.
Uair hits Little Mac on frame 7, but I would assume it's still frame 6 since that would be an odd change to its startup. Granted, this has happened to some characters like apparently Link's jab is frame 8, from frame 7, and his Fair landing lag was increased by 1 from 12 to 13 in the E3 demo build of Ultimate. The difference is that those were animation changes, at least with his jab, while WFT's Uair looks the same, so removing an active frame doesn't make sense. This is what WFT's Uair looked like in Smash 4:
https://www.ssbwiki.com/Wii_Fit_Trainer_(SSB4)/Up_aerial. Anyway, the starting frame is when WFT suddenly shifts from her forward/neutral jump animation to looking down with her arms in Uair's position -- I don't know yoga poses. From there, Little Mac gets hit on frame 7, but I would still say it's frame 6 on startup. WFT isn't shown landing or doing anything else, so landing lag and total frames cannot be obtained here.
The third scene starting at 0:06 and ending at 0:09 cuts to WFT doing Super Hoop. Problem with this is WFT isn't shown being at idle or doing something else before Super Hoops, so I'm going to have to skip the startup of Super Hoop. I would assume it's the same in Smash 4 at 8 frames since there's no real reason to change it as far as I know. I don't remember off hand where Smash 4's Super Hoop landing lag was noted, so I can't make a comparison, but it seems like when WFT lands, it takes 31 frames to return to idle. The starting frame is when WFT lands as indicated by her looking down and not being in Super Hoop's helpless animation. From there, WFT returns to idle on frame 31, the frame when WFT puts her hands on her hips. I'm not sure if WFT could have acted earlier during the landing animation.
The fourth scene starting at 0:09 and ending at 0:12 shows WFT doing Header, dash attack, and Up Taunt. This one's weird and you'll have to slow it down if you a clearer picture of what happens. The scene cuts to lady WFT in the middle of Header's animation and canceling it. Right after that, guy WFT comes running in and does a dash attack on the ball. You can actually see guy WFT shift from his running animation to dash attack's startup shown by guy WFT lunging forward instead of running upright. The ball gets hit on frame 8, but frame 7 is when guy WFT enters the same attack pose on frame 8 and when guy WFT looks up a bit after frame 6. Frame 7 is dash attack's startup in Smash 4 and I would assume they wouldn't just make it slower by removing an active frame like that.
Guy WFT and the ball experience 13 frames of hit lag before the he and the ball move again. If this is ignored and considered the next frame of dash attack's animation, then it has around 44 total frames. Guy WFT begins Up Taunt on frame 45. 44 total frames would be 2 frames slower than in Smash 4, but I'm not exactly sure if guy WFT could have acted sooner, at frame 43 like in Smash 4. Frame 42 looks like he's already at his idle stance. Anyway, assuming if it has the same 6 active frames in Smash 4 with its last active frame being 13, then dash attack's recovery is 32 frames; 45 FAF - 13 last active frame = 32 recovery frames.
The fifth scene starting at 0:12 and ending at 0:15 shows WFT doing a jab combo, Dtilt, and Sun Salutation. The scene cuts to right when WFT is at idle allowing us to see jab 1's startup. The starting frame is when WFT suddenly shifts from his standing idle animation to raising his right leg and right arm and crossing his left arm over his stomach. It hits Villager on frame 5 and I think it's because of how short Villager is and how high WFT's jab 1 hits. In Smash 4, the hitbox below WFT's left arm doesn't appear until frame 5, so I would assume it's still frame 4, but shorter characters and those who crouch can avoid the its startup frame, frame 4. That's just weird. WFT's jab 1:
https://www.ssbwiki.com/Wii_Fit_Trainer_(SSB4)/Neutral_attack/Hit_1.
WFT's jab 2 is still frame 3. The starting frame is when WFT suddenly shifts from his jab 1 animation to turning his body towards Villager and bending his right knee. From there, Villager gets hit on frame 3.
WFT's jab 3 looks like it's frame 5, 1 frame faster than in Smash 4. The starting frame is when WFT suddenly shifts from his jab 2 animation to raising his arms over his head. The weird thing about this is that there isn't a red hit effect like with other moves, but Villager changes into a different hit animation on frame 5, so I would assume that's when jab 3 hits. By frame 6, Villager is buried into the ground. WFT and Villager experience 16 frames of hit lag before WFT drops down a bit lower with his left knee. If that is ignored and considered the next frame of jab 3's animation, then jab 3 has 39 total frames. WFT begins to Dtilt on frame 40, jab 3's FAF. This would mean jab 3's startup was decreased by 1, but its total frames remain the same. If its active frames are the same at 2 frames give it a hit frame of 5-6, then its recovery goes up by 1 from 33 frames to 34. 40 FAF - 6 last active frame = 34 recovery frames. If it's frame 5 because they introduced an earlier hitbox, then it would 1 more active frame, but the same recovery.
Dtilt is frame 9, 1 frame faster than in Smash 4. The starting frame is when WFT suddenly shifts from his jab 3's recovery animation of him standing up to suddenly crouching. From there, Villager gets hit on frame 9. WFT and Villager experience 15 frames of hit lag before Villager starts to get launched. If this is ignored and considered the next frame of Dtilt's animation, then Dtilt has 36 total frames. WFT returns to idle on frame 37, Dtilt's FAF. That's 1 frame faster which coinciding with it being 1 frame faster in startup would mean that it has the same 27 recovery frames assuming it has the same 2 active frames, 9-10 here. 37 FAF - 10 last active frame = 27 recovery frames.
Sun Salutation appears to have the same 21 frame startup. The starting frame is a bit subtle. It's the frame after WFT returns to idle from Dtilt's recovery animation. This frame has WFT puff his chest out a bit as if he was breathing in and move his hands back a bit. Frame 21 is when the sun begins to move which is a bit hard to see. On frame 22, the sun definitely moved a bit. Frame 24 is when WFT touches his toes and apparently that's the frame when the windbox appears? Anyway, WFT appears to return completely to idle on frame 58. 57 was the FAF in Smash 4 and WFT is about to put his hands on his hips, so it might have the same recovery in that case. Recovery frames for projectiles do not include active frames. It's only the startup, frame 21 in this case, and the FAF, which 57 might be. If so, then it has the same 36 recovery frames in Smash 4. Also, Villager gets hit on frame 47. So, it's active for at least 27 frames.
The sixth and final scene starting at 0:15 and ending at 0:20 shows WFT doing standing grab, D-throw, Deep Breathing, back roll, and Side Smash.
The scene cuts to WFT being in the middle of standing grab's startup where she grabs Meta Knight on frame 4. Frame 6 to my knowledge is the fastest a standing grab can be for any? games. At least in Melee, Brawl, Smash 4, and Ultimate. WFT's standing grab was frame 6 in Smash 4, so it's probably the same here and the scene cut to 2 frames after it.
Throws are weird, but it looks like D-throw hits on frame 20, releases on frame 24, and has 60 total frames. The starting frame is when WFT suddenly lowers Meta Knight to begin tossing him up. A blue effect also appears behind them. From there, the hit looks like it connects on Meta Knight on frame 20 where you can see a faint purple hit effect near his mask and on frame 24, Meta Knight hits the ground and launches up. After that. it takes 61 frames before WFT begins her Deep Breathing.
WFT successfully times Deep Breathing on frame 49. The starting frame is when she suddenly shifts from her recovery animation of D-throw to standing up and turning to face the screen. From there, WFT completes Deep Breathing on frame 49. The problem here is that I don't know if it was used before and I don't know if there's data on how long it takes to complete it in Smash 4. There's data on how long it lasts and I believe when you can cancel it, but not on how long it takes for a successful timing.
For back roll, WFT acts on frame 35, but it looks like she returns to idle at frame 33. I'm not sure, but I think all rolls have +3 more total frames. That said, I'm also not sure if she or anyone else could have acted earlier assuming this it the first time or a fresh roll was used. Considering the new mechanic of rolls gaining recovery frames if you use them too many times in a short period of time in Ultimate, I would also not be surprised if everyone's dodges in general were given more recovery frames as well.
Side Smash is still frame 16. The starting frame is when WFT suddenly shifts from her idle stance to crossing her arms over her body and raising her left leg. From there, Meta Knight gets hit on frame 16. The scene ends before we can see WFT return to idle or do something else after Side Smash.