A thought on solving the content gating issue. Long read, pls bare with me.

[Felis]

Sooooooooooooooooooo my thought about this was... Let people start in ilvl90, and in ishgard at the intro for the story of heavensward. BUT!!! for each old phase of the game (in this case its 1.0 and ARR), make an interactive movie/storybook scenario.

Only if the players, who starting the game with Ishgard access, are still level 1 in ilevel 1 equip, starting still in the city with their starting class guild and can't do the 2.0-2.55 MSQ. They can enter Ishgard, but have to first level up to 50 to do quests there with no help of the 2.x MSQ exp they have choosed to skip.