There seems to be no point of reference as to what is working currently other than PvP in Garrosh, other than looking at each one of the update logs, but hard to keep track of what's going on if you're doing it that way. However, there is a link as to what is working on the Legion server. Might not be any correlation, but they at least have a list for that server from what I've found surfing through the Forums.
A couple of buddies and I recently started playing the Garrosh server and were wondering, how are we able to start or get to Pandaria? Also, what all dungeons and raids are currently working? We're specifically interested in PVE right now and would like to know the "ins and outs" of the PVE world of Garrosh, OR should we switch to the Legion version for a better experience?