No, it’s not.
The only people talking like this are negative doomsayers or people who want to give their gripes a talking point.
That fewer people are playing right now is as predictable as the sun coming up in the morning. This game is always a cycle and with the people who just came for something to do after being bored with Shadowlands going back for Dragonflight and with people raid logging now this was going to happen regardless of anything. Wrath is fine.
Anyway on your topic Blizzard already said this:
" As a result, we’ve made the choice to effectively close US and EU mega-realms to new and additional incoming players indefinitely."
[Classic] The unacceptable state of Classic servers - Community / WoW Community Council - World of Warcraft Forums (blizzard.com)