ok... no.
See, here's the thing, wowclassic was out for years without an expansion and did great! why? because it had "content upgrades", a set level and clear goals on how to upgrade your character with that limit in place. What I mean is, there weren't expansions to give you the "xpac blues", aka, the waiting time between expansion announcement and actual release... because nobody wants to work hard for gear that will be replaced in a few short beginner quests.
What wowclassic had was character upgrades. Gear. When a new raid/dungeon was released, you had to work your butt off to get that gear. It wasn't exactly casual friendly either, but both had their place. Depending on your realm, a lot of casuals got to experience big raids to fill spots. Now, it's all gone crazy. I think they shifted things into feeling more grindy than fun. I really miss the days of needing 2 cc classes and maybe a hunter to kite, otherwise you'd get chewed up. And heaven forbid you even try to set foot in an instance/raid if you weren't geared properly.
I feel that releasing expansions more frequently will only hurt more than it will help. Releasing CONTENT on the other hand, would be better. I think having a static level cap, for maybe 2 years? should really help. Because it then becomes about designing content that's gear/setup/strategy dependent, and not so much toss a high level in there and wale away at things.
Anyways, that's how I feel about that.