I'm on board with turning off flying for new expansions, levelling in BfA and Legion was good with just ground mounts, the flight master and flight points gave a good flow even with the limitations, and it's also more fun to fly somewhere when you remember when you had to walk!
But levelling through Storm Peaks the scale of the place is magnificent. Doing quests for Thorim is a drag pre-Master riding, but just the concept of a quest giver living a thousand meters above the zones he gives quests for is just fun. And the view from the Temple of Storms is fantastic.
So, yes, I like flying being disabled at the start of an expansion, but there's always extra zones these days (Nasjatar, Argus, even Hellfire). Wouldn't it be great if the late expansion zones were actually designed for flying, like Storm Peaks? And Shadowlands would be the perfect place to really explore a true 3D zone that's not even limited by the laws of physics.