WQs for Legion raids seem to be missing since Patch 8.1 hit. Unless it’s just been a really bad coincidence that they haven’t popped.
These WQs are sometimes useful for making things appear that are otherwise unobtainable. For example, the fel hippogryph is only available / tameable when https://www.wowhead.com/quest=44938/the-nighthold-love-tap is active in The Nighthold.
It would be nice to at least know if this change is intended or a bug, since alternative arrangements may need to be made for things like this.