It's vastly easier for them to rehash one of their many grind treadmills and slap on some cute costumes and mounts or add furniture for housing and still impress their fans than it is for them to design proper midcore pve content that doesn't involve attaching your leg to a steel ball that is force-carry casuals who hate pve (alliance and "large scale" instances)

I don't see them improving this AT ALL unless they lose most of their casual playerbase. They will give you another deep dungeon and expect you to be content with that for the next two years.