This post on Bulbagarden gives details on both of these things. Level Max O-Powers are only obtainable via events, with Experience and Bargain being distributed at Jump Festa. The interesting thing is, instead of just having an even bigger effect than level 3, they have the same effect, but last for a full hour! Remember, it takes 40 minutes at most to go from empty to full, so you could potentially use this for permanent double experience, among other things. If it sounds broken... well that's why they're event-only, right?
On the other hand, we have something far less interesting. As it turns out, despite a paltry BST of 600, Zygarde will be banned from official tournaments. Three words: ARE YOU SERIOUS? I can sort of understand why they banned Kyurem-N last gen, even though Zygarde will probably turn out to be MUCH better (I'm referring to Kyurem-N's actually impressive BST here), but Zygarde? What do they think is so exceptional about it? Sure, it has Dragon Dance and Extremespeed when Garchomp could only ever dream of having them, but it definitely doesn't have "game breaker" written all over it like some of the mega evolutions do. Furthermore, its ability does ABSOLUTELY NOTHING in OU. So, I ask again, WHY?
Oh, and Item Clause is still on, even though it's been over a decade since it stopped being a good idea. Brilliant, guys. Just brilliant.