For the most part, Falco's frame data outside of what was known with startup and total frame changes is similar to what it was in Smash 4 and also in Brawl and Melee. There were some adjustments like Up Smash and Side Smash's increased damage or Uair's reduced damage resulted in adjusted knockback so that they launched or worked like they did in previous games. Jab 1, jab 2, and Utilt's first hit's lower damage resulted in adjusted hit angles and knockback. Although, I do wish Up Smash and Side Smash kept their knockback values since it's not like they couldn't have been slightly stronger along with the +1%.
The noticeable changes would be Ftilt, Down Smash, Falco Phantasm, and believe it or not, Fire Bird. Ftilt was overhauled where it now has significant base knockback in addition to the previously known lowered recovery at the cost of reduced damage and knockback growth. From Smash 4 to Ultimate, 9% to 6%, 20 recovery frames to 17, 0 base to 42, and 100 growth to 60. So, it's safe on hit at 0 to low percents now, but that also means it can't cause resets due to the base knockback. It lost some utility for being a pure poke tool.
Down Smash finally lost its stupid 80° hit angle on the thigh hitboxes that existed since Melee. You would rarely hit with those hitboxes, but when you did hit with them, it was awful since it could have costed you a kill where you expected your opponent to fly horizontally, but was sent up and not that far. The hitboxes were changed from 80° to 25°, the same as Fox's sourspot hitboxes on his Down Smash. Why the sourspot hitboxes had an 80° hit angle is still a mystery.
Grounded Falco Phantasm was given a late hitbox which is a bit weird since it overlaps from the clean hit. Clean hit is 18-21 and the new late hit is 21-24. Previously, the ground, Falco Phantasm would sent the opponent up at 80° regardless of where you hit during Falco Phantasm. Now, they changed it so that the first half sends the opponent up at 104°, up and behind him, while the last half sends the opponent up at 93°, up and slightly behind. Knockback is also different going from 40 base and 100 growth to 83 base and 50 growth first half and 80 base and 50 growth last half. Not exactly sure why they did this and the move functions more or less like it did in the previous games including being able to confirm a Bair off of it.
Except for being worse as a recovery move and kill move than Fire Fox and Fire Wolf, Fire Bird was fixed in how it hits. The charge hits that used to send his opponent's out at 70° since Melee were changed to 110°, the exact same hit angle Smash 4 Fire Fox's charge hits have, which sends them into Falco. The launch and travel hits now incorporate airborne and ground targeting hitboxes where the airborne target hitboxes has 367° autolink hit angle, 60 base, and 60 growth while the ground target hitboxes has 80° for the launch hit and 65° for the travel hits, 80 set knockback, and 100 growth. Previously in Brawl and Smash 4, both the launch and travel hits had the same hitboxes. Launch hit sent at 361° with 40 base and 50 growth and travel hits used the 365° autolink angle with 30 base and 50 growth.
Some other moves would be dash attack, Dtilt, Fair, Dair, U-throw, and B-throw. Dash attack is the exact same as it was in Smash 4. Sure, buff or change all the other dash attacks, but not Falco's. Can it be stronger? Perhaps a closer middle ground to Fox's and Wolf's dash attacks or do something weird with its hit angle like make it send even more horizontally possibly getting close to a semi-spike if you hit someone near the ledge with it? It's not even used much anymore outside of covering landings or as throw a long, lasting hitbox out. Ftilt out of run is safer, Utilt and Dtilt are more rewarding on hit, and for actual punishing, his Smashes would be better options except not being able to cover as much of a horizontal distance.
Dtilt is 3 frames slower on startup, but was given increased damage from 12%/11%/9% to 13%/12%/10.5% and increased base knockback for the sourspots from 35 to 40. The knockback growth is the same as it was in Smash 4 at 90/88/88.
Fair became slightly weaker with its decreased growth on its last hit from 145 to 137. That's a lot when the final hit does 4%. Everything else except for its lowered startup and adjusted auto-cancel window as a result and lower landing lag like every other aerial in Ultimate remained the same.
Falco's Dair is just plain stupid. People knew that its startup was lowered from Smash 4's 16 frames to 10 in Ultimate from early gameplay footage of Falco. Then it was later found that the clean, spike hit not only still does 13%, but also now lasts 5 frames, 1 frame more than it did in 1.0.8 Smash 4 and 2 frames more than Brawl and launch Smash 4. What's even better? The frame data for the spike hit is the exact same in Ultimate as it was in Smash 4. It did not have its damage or knockback changed for having its startup reduced by 6 frames. It did, however, keep its 51 total frames, so the recovery is longer as a result of not having reduced total frames at 28 frames compared to Smash 4's 22 frames. What was changed was the ground target hitbox has different knockback values from the airborne target hitbox. Instead of sharing 10 base and 80 growth, it now has 55 base and 50 growth which probably explains why Falco can combo and string from it on grounded opponents.
U-throw's laser was brought back up to Brawl's 80 from Smash 4's 60. Everything else is the same. On the flip-side, B-throw's throw is slightly weaker in knockback with 70 base and 50 growth instead of 80 base and 60 growth. The laser's knockback and everything else with B-throw is the same as it was in Smash 4. Falco's B-throw wasn't exactly a strong kill throw and it was the most unreliable one requiring the laser to push his opponent further so that they would go pass the blast zone.