The Orb is kind of the easy answer. No one except for Solas knew about the Orb until after In Your Heart Shall Burn, and the use of Templars/Mages was all hypothetical and people seemed more surprised that it worked than anything.
Both the templar/mage fix not working well and the Breach never closing leads to the same result: people still acting like the Breach is not over. Yet the story never really establishes if this is the case.
I definitely think the order of things / particulars of things changed a lot (as to be expected), but I think in the case of DAI, it resulted in some weird ambiguities, inconsistencies, and underdeveloped elements of the story. Especially since lots of things, potentially story related, were cut it is possible things that were supposed to be developed through missing content ended up being underdeveloped. It's kind of like when you write many drafts of a paper, you may cut things that are important for things to make sense, and not entirely notice when things are gone because you have the context to understand. At a glance, the story of DAI makes perfect sense, but the closer you look you can see a lot of places things start making less sense, see where things could have been developed more, and see where edits were not triaged well.
I think the Orb being underdeveloped is as likely an answer, because if the Breach was meant to encompass the whole game, that cut was probably made a long time ago, where as a few scenes further developing the importance of the Orb in opening or closing the Breach could have been cut really late in the development of the game.