Baton Pass will likely be the next suspect in OU, though I wouldn't be surprised if Lando-T and Mega Meta get put on that pedestal later down the line. I've never really seen complaints about either of those two being broken though. If BP gets banned, Xurkitree usage will dip significantly like what happened to mons like Vaporeon last gen. The thing suffers from being in a meta with so much shit that can kill it easily, be it Lando, Dugtrio, Chomp etc. Its usable, but far from being good, hence why its C on the viability rankings right now.