I threw in Hearthglen as a wild card because it is not part of that legacy. Northern Lordaeron would be a whole new ball of wax. We have no idea what's there.
While Theramore and the Dalaran crater have historical significance, these would be big changes in game. Both would essentially give High Elves their own kingdom of sorts. Moreso if they went with Theramore. Dalaran crater might be a better location for this xpac.
Northern Lordaeron could establish a whole High Elf kingdom that is currently unknown, population and all, which would be a huge change to the world. If anything, I thought some of these choices would be seen as too radical.
That's a great idea! The portals would give High Elf players an actual reason to go there in game.