I think Dragonflight will be a hit with the core WoW player base. As in it wont bring as many people in day one, but it will retain more long term subs. Because the core gameplay loop looks to be fixed "hopefully".
So maybe only 7m subs, but it only falls down to 5m and holds strong? Thats estimating 2-3m subs now. Idk which makes them more money long term though. 2m less box sales, but 2m more subs for a few months? Simple math that I don't feel like doing.