The usmash buff is welcome, but it doesn't solve Falco's core problem, movement. Can't get anywhere in time to punish against a lot of the cast, especially the top tiers. I would've preferred a significant running speed buff over all else.
I'd take both, well, mostly Up Smash's hitbox change and I-frames since it was kind of weird how he was the only one to not have I-frames like Fox, Kirby, Mii Brawler, and Yoshi or it being disjointed for Pikachu which wouldn't make sense, but it still the safety factor that was missing. That and the whole Guile-Fox and Charlie-Falco thing. Also, hitbox-wise, pretty sure all of theirs hit below waist level which finally, Falco's does since it matches the animation. Before, it was weak and not really safe unlike in previous games where it was weak, but safe since it was fast and had lower recovery. It still is fast, still has low recovery, but when Smash 4 was released, people fell out more easily, the hitbox was bad, it didn't work under platforms, and it was weak. The only redeeming things about it was that it was fast, it had high active frames, and it did 16% assuming it connected fully. The same could be said for Zelda's Up Smash and Side Smash at launch - they managed to break them after fixing them in Brawl - and to this day, Samus's Up Smash. Anyway, now, Falco's Up Smash is all of that and some more which might be an issue since it killing about 10% to 20% later and having much higher active frames than Fox's will probably bug people. They could always give Fox his Brawl Up Smash which had like no recovery.
For running speed, Falco should at the very least have a running speed of 1.5 instead of 1.472 because it was his Melee running speed and because being 0.028 off is really, really stupid. Falco running at Mario and Ryu's 1.6 would be pretty awesome while not being overwhelming since that's the average running speed in Smash 4 considering Mario's the average for everything... It's not that bad compared to say, Dr. Mario's running speed or Kirby's when you considered that Kirby's ground was below-average and air speed was low, but now his ground speed is just below Mario's while his air speed remains low since multiple jumps. Air speed-wise, I think it's fine only if this happens: higher air acceleration. High air speed on Falco might be too good since he has the highest jump and having high air speed would be really dumb considering his aerials are fast and most of them have high active frames unlike Greninja and ZSS who also have high jumps and high air speed, but their aerials last less or startup later. High air acceleration would be neat while limiting him to an air speed that wouldn't be stupid since right now, he's got average air speed and if we push him up to high air speed, he'd be Ike and Roy, but with good air acceleration or Greninja, but with fast aerials. So, something like Palutena or Pikachu who also have low air speed, but high air acceleration, 0.1 for Pally and 0.09 for Pikachu. Falco's low air speed of 0.0893 with an air acceleration of 0.1 would totally fine. He'd max out quickly, but still be in a slowish air speed rather than having slow air speed and reaching top air speed like most characters. Also, high air acceleration would just fit with Falco being a pilot, someone comfortable in the air and maneuvering in the air which when you think about it, doesn't make sense how the ace pilot not only has lower air speed, but also lower air acceleration than Fox who is a good pilot, but he's not the "ace" in-universe. Fox's air speed is 0.096 and air acceleration is 0.8.
Other moves-wise, totally be awesome if his jab wasn't a hit confirm for his opponents anymore. It's really stupid when you pick either full jab or jab mixup and still eat hard punishes from characters like Jigglypuff, Luigi, Ryu, and Yoshi while others like Captain Falcon, Fox, Lucina, Marth, and Roy can make it so you are at a deficit from trading what should be from a move that links properly. That's the biggest issue right now since having moves that don't function properly is worse than having moves that could be better.