Shazzrah, Golemagg are full, Gehannas is High, Firemaw is Medium.
If what you say is true, that means only Firemall won’t have queues. But on the actual launch day when many more people will come, I am pretty sure that Firemaw is gonna get to at least High.
What does this leave us with? - Four servers with 100% chance of queues.
What are you waiting for and not willing to open more PVP servers so that people have more time to coordinate with their friends and guilds?
This situation is a real mess and I hope you act fast!