Because of how the game was designed with "center" of the Tamriel being an active "war zone" and PvP part of the game, this kinda "locked" very interesting places & prevented those to be more story / exploration / narrative focused. Those aspects and every potential those zones had was essentially "wasted". ZOS never made that mistake again and every new PvP content (instead of "sacrificing" an actual part of the Tamriel) is a nameless Battle Grounds map.

This however does not mean that there can not be a "PvE" version of Cyro & IC existing along the already existing "PvP" zones. We can play in Oblivion, Clockwork City, Coldharbour etc. So why not a "time travel" story where we could play in Cyrodill or Imperial City BEFORE 3 banners war started ?