I do miss it sometimes but it's already gone. Just having the old 1-60 content around somewhere and never visiting it or doing anything there isn't as it was in WoW classic. Only changes I don't like is that Cata quests outside instances all seem to be solo quests. At least having played through beta and only skipped a few zones, I didn't run into any group quests so I'm fairly confident it's the same at low level.
Oh and also flying mounts .... /hate. Please get rid of them cause I said so, kk