WoW Classic Hardcore’s Self-Found mode is coming in late February, followed shortly after by the Beta for Cataclysm Classic. More news on that will be coming soon.
The previous roadmap shared in December has the Cataclysm Classic Beta banner at the end of Winter, just after Phase 2 of Season of Discovery, which launches later this week.
While the new roadmap now has the Cataclysm Classic Beta banner after WOW Classic Hardcore Self-Found Mode, coming in late February. This gives us a rough idea that the beta should begin sometime around March or April, though an official date has yet to be given.
