How would you feel about going back to old zones instead of constantly adding new zones?

I feel like the Warcraft development team is in a constant rush to keep pumping out new zones with every new expansion, I was thinking about how Cataclysm completely updated the old world and I loved that aspect of it.I'm thinking of old, now unused zones like Suramar. It's a beautiful city with tons of love and care put into it but its irrelevant now. How cool would it be if Suramar was updated, with its own questing hub and its own story?Even small stuff like the Night Fae farming, where the legendary spirits take you on quests to other areas. I'm currently flying through Dreanor. I've never played the expansion but its cool to be able to see the zones.Instead of growing out the game wider, with so many different zones that become irrelevant, why don't we grow the world taller with more depth per zone?