1. There wasn't this much of adapation to be honest in my Eyes, Garchomp and Rotom-W were the only Pokes i have fought yet in real matches and both dont make too big of a difference (Garch makes Sand more Viable tho)
2. Yes it is, i doubt many play Gastrodon, since its speed is that low and makes a huge difference in much cases outside of Trick Room.
3. I guess Rotom Forms have the Potential to still bring a good amount if impact, maybe lopunny is a niche pick with its moves, besides that i guess toxicroak in rain with sucker punch really could pick of some stuff, but testing is still needed in my eyes.