WoW Classic servers are a ghost town
The test world currently has content that was released in WoW Classic's first phase WoTLK Gold, though it includes current updates to the game, including the ability to purchase a world buff saving item from Chromie that wasn't available in the initial WoW Classic version. WoW but was added prior to the release of Burning Crash Classic. The launch of the new test realm is causing speculation among players that it could be a sign that Blizzard is planning for new servers to WoW Classic that allow players to begin their journey into Azeroth all over again all from scratch.
World of Warcraft Classic: Burning Crusade reveals the Burning Crusade
Presently, WoW Classic servers are a ghost town. Blizzard asked players to decide between playing on what it now calls "Classic Era" servers or moving to the first expansion in the game, Burning Crusade Classic, back in June, and it appears that the majority players chose to continue into Outland rather than staying in Azeroth. There's still an active group of players who prefer WoW Classic to Burning Crusade.
A large number of these dedicated gamers are now flocking to servers that are private and unofficial for the game which players have the ability to play on for free but are technically illegal. It's the way that many vanilla WoW players used to do during the time before the official release by Blizzard of WoW Classic and are now returning to due to the State of California lawsuit that claims a workplace culture of discrimination and harassment toward women at Blizzard and the addition of microtransactions, such as the level boost WOW WoTLK Classic Gold and mount in Burning Crusade Classic. Some players no longer feel comfortable supporting Blizzard directly.
