That will definitely play in what I had in mind, basically very hard mode is max level of that story expansion for each dungeon.

Pink Gear drops will reflect that too having max MSQ ilvl + 5 additionally added.

Very Hard Dungeon Roulette incorporates them all from lvl 50-60-70-80-90-100, so all the dungeons will be there restricted to their max level.

Though I would not be against if it was broken down to 6 separate roulettes for expansion for each maximum level range, the only difference the dungeons will be kept separated from eachother restricted to their expansion.