M2K had a multitude of reasons he doesn't like PM Sheik.
As for Falcon vs Ivy, that MU used to be heavily skewed against Falcon. It's improved a tad, but I'm not too sold on the idea of Falcon absolutely winning. Ivy kind of sets up a GG scenario vs Falcon: approaching through the air WILL lose to Bair, and approaching on the ground relies on baiting them instead of anything actually forceful. If you expect things like Ivy DD into Pivot tilts (which would help shut down Falcon approaches even further), then the MU doesn't look too friendly.
The problem most Ivy players have, is locking yourself into a sequence or chain of actions. Ivysaur is a pretty strong character if you do 1 safe option, and then wait a bit. Where you people get into trouble, is throwing Razor leaf and immediately rushing the opponent, or *always* doing aerial into another aerial or into a RL. If you pick one single option, and aren't punished for it, don't commit into another option and give the opponent even more time to get inside and punish you. If you ever do a Bair and drift away without freaking the **** out and needing another attack/hitbox immediately out, you'll see exactly what I mean lol