Rogues yes. Warriors to an extent. Mages maybe to start but maybe not that much endgame. No pet, no mage table, reagents for portals. My first toon in vanilla was a mage enchanter tailor. I’m still paying off loans for mats.

I don’t think WoW: classic will be as over populated/ saturated as classic WoW was. But I wonder if it will be super skewed with 3 king classes.

If you want to go niche play shaman paladin, limited by design.

Out of everything I remember all hunter druids warriors and rogues in PVP. Warlocks too.

Really rare? Go something super niche like ret paladin, shadow priest. There are also some king dead end classes that weren’t fully realized at the time like boomkin.

You can also put 20 in each spec and become super passive jack of all nothings, which actually did kind of work in a mages locks and warriors.