First of all, let me state that i am literally thrilled by most of what have been anounced for 2.2. I love the game and want it to succeed as much as possible.
That being said, and given the information we have, i am extremely concerned regarding the progression of the second coil of bahamuth. I am glad to see that coil gear will now be a tier above tome gear, as i find it silly that people that would never have stepped inside coil could get full i90 just spamming easymode WP week after week. However, most of us have been witnessed that with 2 chests per turn, the RNG to actually obtain gear in coil is quite insane. In the course of 3 months, it is quite possible for tanks to share a total of 3 pieces, and for healers to share 11 (or any other way around, just an example).
With the lockout on soldiery tomes, we will take about 14 weeks of 450/450 tomes to farm enough to get a full soldiery set (assuming 900 tomes are needed for zodiac weapons as it was in the past). Assuming, again, that T9 is balanced as was twintania, gear wise, it means you will need an ilvl of 103 to 104 before you can manage to take it down (blue garter killed TT with an average of 83 to 84).
If no system is in place to counterbalance RNG in coil (which was the point of mythology being i90, despite the other flaws of the system), it means that luck will play a fundamental role in the progression of each group. If you get equilibrate drops that are always relevant (no second brd pants when you only have one brd) and that do not overlap with the soldiery you bought (because if you buy soldiery body a week and the allagan body drop next week you basically wasted 900 tomes compared to someone that had bought the pant instead), you will be able to progress much faster than a group struck by a string of bad luck. It would be totally possible for one group to be ilvl 103 average after 6 or 7 weeks for one team, and to have to wait 12 or 13 for another.
I would be really sad if there was no countermeasure in place to balance out the RNG of coil. It has already been stated that we have lockout so we don't have to deal with low % chance of getting gear. I have no problem with either system, truth be told. But having both lockout in place preventing you to farm gear, and RNG dictating arbitrary how much time you must repeat content before getting an upgrade, is going to make for a very, very frustrating system.