In the English localization of the cutscene immediately following T9 Nael specifically says that the body he is in is not his own. Does he say this same thing in the Japanese version? Surely that would eliminate any speculation that the gender swap was actually fixing up a 1.0 localization error, since it would be unnecessary in the Japanese version?

Also if there was an error with Nael's gender in the 1.0 localization why did they even have Nael lose his helmet? Given how we're still unsure of the identity of Nael's new form there was really no reason for them to even unmask him unless they deliberately wanted us to speculate on the body swap.

Nael's new female form was revealed too deliberately to just be a cover for a mistake. They could easily have just kept it hidden but they chose not to which tells me there is significance to it. If anything the fact such a big deal was made of it with no concrete answers suggests to me that we're not actually finished with Nael's story.