I remember somewhere that a dev said they eventually wanna make portals phased out. mid way expacs have no other way to get to thier lands except by portal while other expacs have transports. the exception being outland and draenor since in lore thats the only way to get to them. Thats also why there are boats now to boralus and zandalar which is great for my low level RP alts who are below 100 or so.