Returning to the statement now I've got time to do more than abuse.
Between every character above Samus, Falco has the hardest time against her. Falco's laser and shield pressure games are very bad against samus' shield and poke game.
Lasers: How? How are lasers weakened? They, like with many characters, keep her locked up in that shield with those awkward OOS options (more on this later), they make damn sure she's staying grounded (not that Samus can do jack in the air anyway), she doesn't have the capacity to camp back. Please, explain how they're "very bad".
Shield pressure: Samus has a ****ty SH and is pretty helpless in the air, so that's not good. She can't shield grab with the slooooowwww grapple, so that's not good. She has up B for a while, but if the Falco's not digging deep and spamming tech, he can control that too. Falco can come in with simple, conditioning strings of aerial>shine>to get out, and Samus can't do jack (or, if this Falco's actually clever, start mixing in all that fancy **** that ***** like shinegrabs and doubleshines to throw them off). Up B is a BIG RISK with either a kill or a combo (yeah, falco actually combos Samus, that's neat) waiting on false prediction. Even if you get it off, players like Mango SDI into the ground consistently for 1% damage anyway. The risk-reward is stacked against her. That leaves WD back, which Falco can follow and continue the cycle, or if he's not feeling certain just leave it. Boom, reset to neutral, repeat till mistake. Falco is controlling the pace, the onus is constantly on Samus.
This all sounds very bad for Falco.
edit- actually ICs might be worse than Falco against Samus. I guess that makes falco 2nd worst against samus.
I don't care about comparative matchups. We're talking about the matchup in a vacuum, who has the advantage.