Speaking of which, Gardevoir, Pory2 or any other tracer would be hideous to face against a trace oriented team. They will be prepared to dish it but simply will not be prepared to stop it.
+2 evasion isn't SO bad that it needs to be banned, I think. Yeah, there is some luck involved but that is inescapably built into the game with crits and the ideal that every move isn't 100% accuracy. If you don't like it, I'm sure there are other games where luck doesn't play a role (see: chess). The idea that it can +6 evasion while -3 random stats WHILE moving (with two protects) is disconcerting, but I'd like to think I can mitigate a smeargle/bibarel/whatever with my well thought out team BEFORE it gets to that point and I'm not exactly the savviest of battlers. Not to mention this game is TAILOR MADE for accuracy and to minimize risk, so some fucker coming in on your *typically* highest accuracy possibly moves should be a cake walk. Not to mention No guard Machamp is still at large.
I think that proposing to ban this is cowardace; it gives mons like Octillery a chance to ACTUALLY EXIST rather than be in a tier that we may get around to 2-4 years after the generation comes out.
I think this comes down to people be unprepared for it. It is no worse for hax than scarf flinch jirachi or wonder guard and certainly no worse than wondersash, which single handedly can win games if played right. Hell, if anything this should make a defensive bibarel legitimate as unaware (unless I missed something) RUINS this shit.
I worry about a metagame in its infancy and flying the flag of "no early bans" flustered about a bibarel or octillery that COULD (1/7 chance, at the end of the turn, if you don't OHKO it when it switches in) do some damage to your team of potentially very potent pokemon.