I think the word "apparently" demonstrates well enough that I'm speculating on previous and current information, yes. Insofar as the explanation goes, it does makes sense to me at least - I didn't think it was hard to understand. I crouched both possibilities as well, both that they may or may not go to Oribos to be judged, and returning to Azeroth as a wisp is apparently a possible afterlife by dint of the fact that wisps exist and we know they're departed Night Elves. QED.
I'm not saying that the lore in Shadowlands doesn't cause conflicts with previous lore, simply that the existence of wisps isn't a conflict - it can easily be understood in the current model, in any of a few ways. We already know that Kyrian Bearers don't always transport souls to Oribos, as they don't do so with the souls of the undead, Liches, etc. etc. They also allow certain souls to be resurrected if it serves the Purpose in some sense, such as the example of a Mantid warrior fighting a Necromancer. Wisps might be another exception in a positive sense, or the Arbiter sends them back to Azeroth to serve out their assigned afterlives.