Originally Posted by Blizzard(Blue Tracker / Official Forums)

As we read most everything posted here (and elsewhere) about next week’s content update, we can’t help but be impacted by the subject of transportation portal removal. It’s a subject that’s approaching 5000 replies in one thread alone, and the question raised there, repeatedly, has been, “why?” Here’s the answer to that question.
From the beginnings of World of Warcraft, game designers have had a number of guiding principles. Sometimes these notions change quickly, and sometimes they evolve slowly, but a few guiding principles have remained more or less the same throughout WoW’s history. One such lodestar has been “don’t overuse portals between locations in the world”. Too many eliminations of the distances between places can diminish a sense of the world having a meaningful size.
Of course there’s an equal and opposite design consideration—“don’t make it too inconvenient to get from most places to most other places”. Some amount of convenience is vital. Not every visit to a wondrous landscape is your first. We know when it’s your 100th visit, you don’t want the flight over to be the bulk of your time spent. And of course, some players have chosen to play as Warlocks or Mages specifically because those classes offer unique means of transport.
With new expansions, we’ve made a tradition of removing some of the portals from the previous expansion’s cities. The goal with that is to encourage transportation flow through newer places where players are more likely to interact with other players. We neglected to do that initially following Legion (and we never did that following Mists of Pandaria for various reasons), but we feel that we should have. We’re correcting that now.
Boralus and Dazar’alor will continue to offer portals to a full range of capital cities, as well as to Silithus. The portals to Cataclysm zones will remain intact, and many other modes of transportation, such as Dalaran Signet Rings, Karazhan’s ring, the Timeless Isle trinket, Coordination Cloaks, and boats and zeppelins between many regions, will all be retained and functional.
However, we’ve seen how updates to the game can leave the means of accessing different areas feeling increasingly chaotic. For example— today if you go to the Cleft of Shadows in Orgrimmar, you’ll find it dotted with portals in a way that almost looks sporadic. We’re cleaning that up, and we see this as an opportunity to consolidate a lot of travel into a consistent venue with a consistent look and feel, and room for future growth when needed.
We’ve processed a lot of feedback on this, especially feedback about specific locations that feel like they’re going to become disproportionately inconvenient to reach, and we’ve followed that feedback through to the conclusion that you’re seeing on the PTR. We believe that the numerous remaining means of quick access in the game make most locations quite reachable.
If there are any specific locations that feel as though they’re about to become unreasonably inaccessible, we’re certainly open to adding additional means of travel in the future.

Originally Posted by Blizzard(Blue Tracker / Official Forums)