Isn't the simplest solution the likeliest one, that they've duplicated the entire zone for the phased version (due to the zone wide skybox) and are going to focus on the area around Icecrown Citadel for where the action is?
Who knows? Perhaps as the update of the zone progresses they may remove the Tournament to reflect the passage of time but it's probably a mite more convenient just to leave it and it's associated NPCs in place so people can access the vendors without having to go backwards and forwards through Zidormi.