I understand the economics of MMOs, but they need to start being smarter with their content. Refresh old content for existing player base.
i.e. Make a level 60 8-man version of CT-ST-WoD. You can normalize all of them to be a similar difficulty (maybe slightly higher with each), give the mobs adjusted stats for 8-man level 60 so there's a bit of a gear check difficulty and then make the 3-way intersection sections into 2-way intersection sections where the PT splits up into 2.
So there's a decent amount of work involved with balancing and play testing, as well as re-designing some of the levels. But all the artistic work and asset work is all done, so it would be significantly less development work then a new raid, but provides a new experience (8-manning content that was for 24-man, adjusted difficulty to level 60s, etc)
Again, doesn't need to be hardcore. Just needs to be a decent difficulty like an EX Primal so everyone can enjoy.
Then once you make that content, you should make it so you can only run it a couple times a week. Why do we gotta gear up so quick? Repeat this process for other content, so every week you have a varied schedule of things and aren't running the same content over and over.