I have done some intern work at blizzard and seen and heard a few pieces of information about the future of Shadowlands and the next world of warcraft expansion.
9.2 is the last patch of the Shadowlands the patch takes place in Icecrown with the final boss fight being the Jailor at the frozen throne Anduin is the penultimate boss I don't have much more info on this because I have only seen some concept art.
Season of Mastery will launch sometime in November with 9.2 releasing end of q1 2022.
I have seen some art and assets for the next expansion. It will feature a remade Eastern Kingdoms and Kalimdor. Gnomeragen is an actual city the undead have cleared Stathholme and that is a new city.
I have seen some models for player housing beds, drawers and different house tiers ect but I don't know how it will be implemented.