Well this is killing my interest in TBC classic quickly. Why can't we play with cross-realm friends again? Servers are arbitrary barriers anyways.
If you have such a large social network and they all play classic WoW, instead of retail, another mmo, or another game. Then I seriously doubt most of them would want cross realm. Most people who play that version of the game, play it for the advantages AND disadvantages it had. That is classic versions target audience.