It comes from a behind-the-scenes leak reported by YouTubers Taliesin & Evitel. They tweeted on 1/23/2022,
“The way I’ve heard it (and that’s all it is) is that Afrasiabi was set on Sylvanas’s turn in BfA and was moved off the team (for now obvious reasons) after it was announced but before it was properly worked out. A ‘Dude trust me’ that he never saw through.”
More information, including a link to a video with screenshot, is in this thread: