Fix the queues. You created this problem by allowing people to transfer to these already very large servers before the pre patch was released. Your bandaid fix of allowing transfers is fracturing friend groups and guilds, setting that server up for population issues should the players who were COERCED into transferring to it have an opportunity to return to their original server.
The explanations blizzard offers which draw comparisons to 2008 technology and what can or can not be done (irregardless of budget, don’t want to upset the Microsoft deal), is beneath a company that tries to deliver a quality product, yet boasts a poor record for launches.
Support mega servers.
Admit you created this problem, and fix it.