I wouldn't go as far as saying ilvl90 is going to be the new "DL" tier...
If you limit yourself to 1 Main Story Roulette, 1 Low Level, and 1 CT a day...that's 600 Phil...enough for any accessory, any visible piece other than body/legs or combos. That's about 3-4 hours hopefully depending on what job and competency of the group (Yeah you can do this in 2 hours, but I'm being conservative).
Now I'm new to coil, so forgive me if I don't have proper expectations...but that would take 12 runs of coil to meet. At say 30m a run, that's 6 hours. At 20m a run, that's still 4 hours. This all assumes you have a good enough group that even with changes you can cruise through, and no wait time between runs or lfg
I think you'll see a drastically easier time, but for myself and my FC folks who are non-legacy, none of us have full relic, I don't think anyone has Allegen gear either. However most of us when we get new jobs to 50 has a full DL set waiting there from CT and other stuff adding tomes up. I don't think we'll be able to say anywhere near the same about Myth...I think it'll be something to work towards, and a very attainable goal, but unless they increase the amount of tomes you get per run, I'm not sure it'll be as easy as "DL Tier" was to attain.
My 2 gil :p