When classic starts everything is fine… but when it moves to TBC classic and so on, there’s always those who want ‘‘fresh X classic’’. So, my suggest is, when next classic turns to TBC classic… make a new classic server, and let people choose: either continue into TBC classic or transfer their character(s) to new vanilla realm, with squished levels etc. and when tbc turns to wotlk, same thing. And reset these realms in 12 month cycles. So there’ll be 3 classic servers, 1 for each.
And, for god’s sake: let us KEEP legacy mounts in retail version, similiar to MoP remix, transmogs, mounts etc you earn in classic: you earn in retail also. Its a good way to get those old legacy mounts, which would be nigh impossible to get otherwise. Even the gladiator mounts.