I don't see the usefulness in chain rooting mobs in PvM, outside of soloing perhaps. In fact, that'll be pretty annoying if teams want to mass mobs and stack them in one area or are quick moving teams. I guess crat should never enable those procs in most PvM encounters again.
Chain stunned bosses are not fun. The game is easy-mode enough already, even with this significant change. Oh no encounters might need a better than half-assed tank and half-assed heals now. Yippee!!