Honestly, I see no reason to ban anything from DW OU. As it is, the metagame is balanced, despite, or perhaps BECAUSE OF, guys like Soul Dew Latis and Shadow Tag Chandy.
Unless the set that got him banned on the PO server becomes provably broken here, Chandy is perfectly healthy for the metagame. Scarf Chandy (the most popular set) is like ADV Band Dugtrio. The guy traps and revenge kills things, including the Latis which are so "broken". Meanwhile, his typing means any fast pursuiter can come in and revenge the revenger, not to mention Ditto wipes the floor with Chandy provided he's locked into an attack not named Shadow Ball. Also, weather wars exist. Which means Tyranitar and rain exist. If sun was the dominant weather you'd make a solid case, but as it is, Chandy deserves to stay.
The Latis, with their soul dew, essentially get one calm mind for free. I get it, that kind of power is amazing. But the problem is that they're dragons and psychics. The metagame has adapted around dragons, and life isn't too kind for psychic types in this metagame, or any other post-RBY metagame either. Most sets carry a dragon move, surf, and psyshock as their attacking moves. Even with a rain boost, specially defensive Jirachi walls the twins to hell and back. So does T-tar with the right EV investment. I've seen plenty of Pokes beat a Lati one on one despite the soul dew. And remember, soul dew means no leftovers. Sand is their enemy. If you can get off a t-wave (prankster anyone?) you're good to go, and toxic and WoW wears them down too. And let's not even get started on Chandy and Genesect.
Remember how people say Ubers is the most balanced metagame because the things that would be broken in OU are checked by each other? This is kind of like that, with OU Pokes checking them as well. as long as T-tar, Jirachi, and Genesect stay in use, the Latis aren't anywhere near broken. And as long as rain and pursuit, and SR, exists, Chandelure with Shadow Tag is fine too.
Also, Excadrill and Thunderus. Not broken in DW OU. Not at ALL. And with Ditto running around, Blaziken is less broken than he was in "Wifi" OU. Veilhax kills Chomp but what can you do?