Excadrill would be healthy for this meta IMO. It can switch-in to non-Focus Blast Thundurus-T and Tornadus-T. Gliscor, Amoonguss, Conkeldurr, and Landorus-T counter it, and Keldeo checks it. Also, it spins and gets Stealth Rock, which is cool. Also, sand needs all the help it can get ATM.
Garchomp would also be fine. With rain dominating, Sand Veil is not as big of an issue, and multiple new threats can beat it, including the Therian genies and Keldeo. Also, Haxorus gives it competition for a teamslot. Oh and Ice Shard Thick Fat Mamoswine.
Thundurus-I (like the others) seems okay. It looks like Thundurus-T outclasses it, and Tornadus-T can check it. In addition, Regenerator Amoonguss and the more useful now Gastrodon beat it as well. Ice Shard Thick Fat Mamoswine is a thing.
I'm on an iPod and don't want write a whole ton now, but other than Shaymin-S I could totally see AfroThunderRule's list of retestings being viable.
EDIT: If this sounds stupid then sorry, or if whatever examples don't make any sense. Also sorry if this isn't the appropriate place.