This is a completely brainless idea.
Yes, let’s not let people play the content they need to in order to get more geared /sarcasm.
They already scale up gear to 250-something. The bigger problem is all the other Borrowed Power nonsense that exists in order to be strong: 2x legendaries, conduits, renown, etc.
All this will be solved in Dragonflight with the removal of Borrwed Power systems and a significantly more flat gearing process.