Hasn't Falco been said to have a good Bayo matchup or am I mistaken?
As Gamegenie said, it's bad. Pre-patch Bayonetta was definitely a -3 for Falco. Post-patch? Still -3. We're talking about a character fighting another character who has essentially does everything he does, but better and some more.
Someone to ask / watch with the most experience would possibly be Lada, but he's a ROB main. I say Lada since he commonly fights against Caculus. Remember that one player who was carried Bayonetta? Oh, wait. None of them exist. Another one might be Josue, but I don't know how often he fights Bayonetta players and I don't think he's a Falco main... Capt. or DK. Also Osiris, but last time he was mentioned here, he was shown ragequitting. I don't know if Keitaro has any extensive Bayonetta experience nor do I know if AC, Anragon, etc. have any.
The only thing Falco really has on Bayonetta is possibly the fastest punish on Bayonetta players auto-piloting with Witch Twist set-ups. Why do I say this? Bairs are generally good moves, so... Why are you letting Falco's back face you if you happen to drop your set-up? Yeah... That's pretty much it, though.
Falco has no such thing as a "good matchup".
Ha, you should see my MU spread for Falco. Makes Charizard, Robin, Samus, and Zelda look like Melee top tiers with their recently posted MU spreads.
falco has been said to have a good matchup with mewtwo because alot of his tools can cover mewtwos landings and falco doesnt lose neutral AS HARD to mewtwo as other characters make him do. Well thats what the mewtwo and falco discord groups have come to an agreement on. But falco has no good matchups so i dunno :^)
I can't see how Mewtwo who severely out-ranges, out-kills, and out-speeds Falco having trouble with him. If the Mewtwo Discord is in agreement with having trouble with Falco, then they're playing the game wrong. Not the MU, but the game.
There's some Falco vs. Mewtwo sets on YouTube; two sets of Zanryo vs. Mew² and and one set of Kato vs. Hitaku. It's how I learned Mewtwo's jab to Up Smash is a thing.