In a previous post discussing server transfers, Blizzard stated the following: “Pagle & Grobbulus will have their realm caps increased to effectively unlimited”. This, however, does not seem to be the case, with players being placed into a queue while trying to log in.

This issue has been brought up on the WoW Classic Mists of Pandaria forums, with a player pointing out the same quote that said queue times won’t be a thing. With a very quick response, Blizzard has addressed the issue with the following statement:
Fixed, sorry about that, the new limit was taking effect on weekly restarts as we were still a good way away on Friday, but lots more showed up this weekend, this has been raised now already and won’t be seen again.
This oversight was likely caused by the recently unlocked character creation, where Blizzard opened character creation early on the new Connected Realms. Rather than waiting until Tuesday to increase the character limit, as was previously planned, Blizzard has increased the limit immediately. This is a very swift response from Blizzard on the issue, and queue times seem to have disappeared with the update.
Many players, however, remain unconvinced, believing that peak raid times on Tuesday will again see a login queue forming. Only time will tell, as more players utilize the free character transfers to these new mega-realms. With such a quick response from Blizzard on a Sunday evening, we remain optimistic that Blizzard will be monitoring and appropriately handling any future hiccups with the new mega-realms.