[unknownzero]

It's worth noting amidst all the debate about whether it's feasible or worthwhile to offer older versions of the game as server options, blizzard has already done this for a long time with Diablo 2. You could (can still) choose to play classic or expansion on the legit battle net servers, and both had ( possibly still have ) vibrant communities. So it's not like this would be particularly novel as an idea to them, I'm surprised they haven't done it with wow already.

[Shivetya]

with their constantly dropping subscription numbers it might just be a good idea for them business wise to open specific expansion set servers.

[debacle]

I would honestly pay to play pre-BC WoW again.

The real problem that Blizzard seems to have is listening to their users - they're constantly making changes based on the feedback of vocal groups of players or trying to simplify their games to be more appealing. They have some of the most valuable IP in gaming and I feel like they're not making the most of it.