Maybe. I mean personally, I’m having a blast, and I would hands down prefer a large population server over a lower population server.
But yeah, it could well be the case that some people would prefer smaller population servers.
I mean, depending on how one chooses to define faction balance, Whitemane is showing as 47:53 based on the last 14 days of activity of level 60s: https://wowclassicpopulation.com/characters?lastSeen=14&minLevel=60&realm=4395_Whitemane, which is about as balanced, I think, as one would like (that’s also a little over 10,000 characters though).