The non-Remix version of the quest “The Best Around” continues to demand that you ‘Take the portal to Deeprun Tram’, a quest step that continues to be impossible to complete, since no specific portal to the Deeprun Tram is provided at Lion’s Landing in ordinary retail, and no other portals, neither temporary or stationary, are counted as sufficient for the quest step, not even manually walking into the Deeprun Tram from Stormwind or Ironforge.
The Operation: Shieldwall storyline of the Landfall campaign in Pandaria remains impossible to progress in ordinary retail.
EDIT: Some good news! The temporary portal to Stormwind that you can purchase with Domination Point Commissions works now for the ‘portal to Deeprun Tram’ step. Haven’t checked any others, though.