It seems like only one boss will be released each week. That means it might take five weeks for mainland players to see the final boss of TOC.
I'm planning to level up my druid ASAP, trying to be the first druid or even first player to hit 80 on Maduolan. Any1 who is also interested in making history plz PM me. I will help you level more quickly, by aiding you with food, elixir, and even lvl70 epics.
PS there is no random dungeon system in 3.22.