I'd be ordering a digital CE from the SE store if that makes a difference in all of this.

I see on the document linked:

A Realm Reborn Adjustments

Aimed at making access to Heavensward content easier
Main Story Quests exp rewards “more than doubled”
Post-2.0 Main Story Quests give equipment rewards.
You will be able to go from New Player → Heavensward without having to do sidequests, gear from MSQ will be enough
Duty Finder will prioritize people running content for the first time
Level 50 A Realm Reborn era will still give 0 exp.

May be adjusted at a later date.
So is the MSQ up to 2.55 considered "A Realm Reborn era?" If so, that would seem to indicate that you wouldn't get xp for it even after the xpac releases.