[nikanj]

The cost of running WoW servers per player must have plummeted in 15 years, thanks to both better devops and better hardware. They might be ok with a freemium model.

[falcolas]

If they haven't moved WoW proper to a freemium model, I highly doubt they'll do it for Classic.

Look at EQ. The base game is freemium, but if you want to play on the latest progression servers, you need to pay their subscription price.