Yep, there is no standard Raid UI for this game telling you "HEY, USE YOUR <Insert Skill Here> NOW"
Just keep an eye out on your frames and you will be fine.
Plus, tankasin's = the tankadin's of SWTOR. 7 Seconds of spamming and building threat, followed by 30 seconds of "Thrash, Thrash, Proc, Thrash, Thrash, Taunt, Thrash Thrash, etc..."