I imagine it's going to be more of an FFXI problem when they raised it from 75 to 99. Even the jump to 85 invalidated basically all gear that had ever existed during 75 cap save for a few, they also let others be augmented. This means a new player will join and level to 60/75 or whatever they make the new cap at and have better gear from leveling dungeons than people who had a full set of High Allagan.

They will eventually settle on a long term cap but prepare to see butt-hurt people if/when the cap is raised.