The two servers, Herod and Shazzrah are so popular that blizzard advises finding another server.
If nothing has changed at this time, it may be that the login queue exceeds 10,000 players.
Blizzard does everything to make the launch of Classic go as smoothly as possible, but with this type of omens it can still be difficult for them.
Although there is a lot of difference in the capacity of the 2006 server shy with 2019, Blizzard is not prepared to expand that even more.
Posted by Kaivax
Based on name reservations so far, the Shazzrah realm is looking to be massively overpopulated. If all existing players on this server remain there, login queues in excess of 10,000 players are a certainty, and possibly much higher than that.
We recently opened up the Gehennas realm, and we urge players on Shazzrah to consider moving there. There are a lot of players currently on Shazzrah and we want Gehennas to fill up before we open any new PvP realms. This is so that player population is spread as evenly as possible before launch, in order to provide the best play experience.
While we are able to fit several times more players on a single realm in 2019 than was the case in 2006, we are not going to raise that cap any further, even though we have the technical capacity to do so. Raising realm caps would simply forestall the problem, letting more players in at launch but creating an unsustainable situation down the line, with severe queues when we turn off layering permanently before Phase 2 of our content unlock plan.
Please also note that our realm population estimates of Low, Medium, High, and Full are based on this increased capacity – a Medium realm today already has more characters on it than even the most crowded realms did back in 2006.
Our top priority in planning for WoW Classic’s launch has been ensuring that we are laying the groundwork for strong realm communities that will endure over the months and years to follow, which is why we’re cautiously opening new servers to meet demand.