There aren't any, really. Tangrowth was good, but not an influential Pokemon in RU ever since Venusaur dropped. There were a couple neat things it could do that other Pokemon can't replicate, though. Its AV set was pretty nice for certain balance builds since it enabled it to check a lot of things very well, particularly Flygon, Virizion, and Meloetta, while actually doing something vs defensive teams by spamming Knock Off and being a Pokemon Alomomola wouldn't want to Wish pass against, so balance teams lost a decent blanket check to several Pokemon and a pivot that didn't forfeit free turns to certain defensive cores; however, Tangrowth doesn't leave a void that's difficult to patch up for those teams anyway. Other sets Tangrowth used were outclassed or unspectacular. I guess the biggest change, albeit minute, is that Water + Grass regen cores are officially dead in RU, but that's about it.