I agree with all but alolan dugtrio. I was thinking the other day how it found success in Let's GO as a stealth rock suicide lead to hanks to its steel typing and high speed. Planning to experiment with the possibility of it in SS OU once Showdown allows them to be tested despite Excadrill existing.
I don't see much what they can do, maybe we see some gimmick with Alola-Raichu and Pincurchin due to Alola-Raichus ability on electric-terrain.
But otherwise I just dont think they will offer much for Ou-purposes and thus will drop down tier after tier