I dont understand his logic that for a new expansion he needs to increase level cap and that takes time. You can still develop new content and keep level cap at level 12, if that is going to break the game engine.
You can, but people don't like to be stuck at the max level for half of the game. Add a significant amount of content, and the percentage of the game players will spend with no more advancement prospects will increase. That's very much undesirable.
