Own all the previous chapters, but all the doors in the Keywright's gallery are locked.

[TheFilthmeister]

Do I have to progress to access these zones, or is there something I'm missing here?

[Andrey]

This is from Update 41 patch notes:
"We’ve updated the post-quest tutorial portal room so new accounts will be initially limited to the portals to Stros M'Kai, Bleakrock Isle, and Khenarthi's Roost, depending on their alliance. Upon using any of the aforementioned portals, you will gain the ability to use portals to any additional zones available to your account as well as the ability to skip the tutorial on subsequent characters."

[TheFilthmeister]

^^^ Beautiful. Thank you!