They are probably looking at this as well:

http://store.steampowered.com/hwsurvey/?platform=pc

There's more than just pleasing a customer that is taken into consideration when developing something. Here are some examples:

Internal/External Customer Satisfaction
Initial Cost
Technical Debt (how much this will cost after it's done to maintain)
Market Desire
Current/Future Roadmaps
Device Support

If they come out with this and it keeps happy or gets X people; but in the end they lose money on it or waste valuable resources. They might reconsider. More than a few hundred million has already been pumped into this game and even more with the upcoming expansions and what-not.

I'm sure they are considering it; but don't be surprised if they say no or just say "make your own".