I'm unsure about a Roulette style for this too, if they do it they should at least make it so you only have access to it once you cleared all of them once, else it would be a wipe fest by default.

What I personally would like to see is some sort of Primal Focus 2.2, with a weekly quest for clearing the 4 'newer' ex primals, or even get rid of the old quest and make a new one where you have to clear all 7 (or 8 if you count Odin...). Of course this quest should give rewards that are not completely outdated, especially since running the CT weekly already gives coat/twine while the considerably harder Primal Focus quest only gives i90 weapons.