I have been saying for a decent amount of time that the writing is on the wall for SL to be the last expansion. Perfect time to end it when you have Classic expansions you can launch and D2 remastered while you work on new games and MMOs.
So when WoW 2 does happen well it’s a fresh start a new game on a new game engine so it’s not an expansion but a different Universe and game entirely.
Keep in mind they can just roll out WotLK Classic then mini patches for SL till WoW 2. The way they been doing SL patches that means 9.2 in 2022 and 9.3 in 2023 maybe a 9.3.5 then in 2024/25 WoW 2.
PS - SL and the last expansions were so sooo bad it’s time to end this. Don’t think anyone can take another one and 8 expansions is a good run. The time is now to work on WoW 2.