In theory, one could say all gear will be iLevel from lv 50 on up. So and piece for lv 51 ~ 60 would read like lv50 (equip) iLev 55, same as normal. The difference would be the players base stats for the job/class and abilities/traits available. Currently the ilevel stats across a set should put player stats to that range. If anything were getting a bump for content, but it also means we may not see much in stats in ilevel gear in the future. Unless new gear picks it up at i145 being i135 is about the max now before the extra 10 levels.