I'd lost all hope of Mew2king performing well, with regard to both Brawl and Melee, at APEX, but his recent flurry of successful activity has me intrigued.
Predictions are largely useless until I see the bracket though.
EDIT: Also, Armada's probably (~80% positive) still winning. Person with the best chance of beating him is Hungrybox, but he'll guaranteed lose to PeePee or Mango, should they meet in bracket beforehand.
The only players I'd describe as "wildcards" (capable of potentially cracking the above four) are Mew2king, KirbyKaze and Javi (and, due to pretty insufficient data, I'm not certain I can call this one). That's literally it, IMO. Melee's skill gaps are dumb.