The server populations are already extremely large. If the caps are increased even further then how exactly will it feel any different from cross-realm and sharding? Imagine funneling a huge population through the few zones that are available at level 25. Imagine 50,000 players in Ashenvale. The amount of layering will be staggering. You will never meet the same person twice. Layer-hopping will be even more overpowered. Did Blizzard forget why they implemented layering as opposed to cross-realm sharding in the first place?
This seems to me like they’re just trying to cut down on server maintenance costs with total disregard for the effect it will have on the game.