No it was stated last e3 that they are introducing gaming without generations. Maybe you missed the press conference.
No snark required. Aaron Greenberg said "We think the future is without console generations." That isn't proof of their console strategy for the next ten years, because, honestly? Microsoft says a lot of things.
Microsoft isn't going to let Sony release the PlayStation 5 as the only actual generation 9 console, that would be market suicide.