I don't know where you're gettin your info, but I know many including my own guild 3 healed it(2 tanks) pre-nerf.
I don't know how hard it is as a shadow priest to manage mana, but it's definitely worth a shot to dispel if your healers are going oom, and even though you can't control where the debuff bounces to as well, it shouldn't matter with this many nerfs.