this only prove how successful is lfr compared to other difficulties, blizzard since mop is desperately trying to drive peoples away from it, first by removing mounts, titles and achievements, in wod by removing sets and trinkets and by making the followers unavailable, in legion by making some quest not doable.
Without even counting Karazan the main focus of 7.1 patch not being available in lfg, it's clear that some devs are really butthurt by lfr, now if that is because they have an ideological aversion or because an upper echelon has begun to question if they really need to invest so much dev time on non lfr difficulties i don't know, but they are bent head to toes into pushing peoples outside of it.
I only expect more heavy restriction being applied from now on especially if the mythic and mythic+ after so much time invested proven to be only a niche activity by the data they collect.