Is there any lore justification for being able to do previous expansion's sidequests?

[crowwww]

[*]Alternatively: what if you ALREADY did it? Screw linear time; if it makes sense for your character to do a questline, then they did it back when it was roughly taking place. You want to say your character was studying to be a monk back before the liberation of Ala Mhigo, like in the ARR story? They already did, you can just say that! You're the character's writer, what you say goes.

I've always liked this way of thinking about it, especially as you can then (broadly) sequence things either by release patch or by the quest's level (or the level within the patch; Island Sanctuary are Lv 1 quests post Lv90 EW gwhaha)