The threat on Beluterra of Daimons invading all the worlds of BattleMaster is what had me wondering. I'm curious, what formation did you end up with?
I assumed all continents had their north upwards, as that's the traditional way of displaying maps and I believe switching them over would have been a trivial exercise at continent creation (probably wasn't thought of, but it would have been a good idea). I started out with the old spellmaster map, and then used clues to place the next ones. For example, BT was west of the original continents, because the first lands colonized were on the eastern shores. Dwilight, originally called Western Continent, was even further West for the very same reasons. BT and AT were slightly more north than the rest of the continents, since these are the only ones that actually have snow. The southern islands have a "west" and "east" which helps determine where they could be.
The continents that are carbon copies of each other could be flipped to look less dubious. For example Belluaterra's north could be Atamara's south.
It's possible, but rotating a map up-side down makes it unrecognizable for lots of people. And as I said above, were that the intent I think they'd have already done it, I believe rotating it now would be a lot more trouble than it would have been at its creation.
Established RP also always said that North was up, both on BT and AT. The RP rule typically goes that the first to state such things makes it true, and since a lot of people have been saying it for all that time, it'd be inappropriate to say "no, your characters were stupid all along, North is the other way".
That being said, it would open up different possibilities of continent spreads that would be much more appealing to the eyes than what current indicators suggest, if a unified geography map was ever desired. Imo, the best way to proceed to such a thing, however, if it truly was desired, would be to use the daimons as a pretext to change the geography of the continents, to remove parts of lands and add others, in order to make them different enough that seeing them next to each other doesn't undermine suspense of disbelief as much anymore.