I think it might be complicated. If you look at this bit that made raveloft a particularly frightening place to be in the past
and compare it to the similar attempt from ToA that do almost nothing to short rest classes but really hurt long rest classes in the very situation where they should have an edge over short rest classes it becomes clear that the short rest ability heavy classes create a problem that should probably not be expanded upon until they can start coming up with solutiond.