I actually proposed that idea a long time ago, to explain Cyndane's lesser strength. The idea being that the body can affect the strength of female souls, but not male souls. So, Cyndane is (unluckily) weaker than before, but Moridin & the 'Gars are the same strength as before (even though Aran'gar is in a female body, she's a male soul so the body doesn't affect her strength).

One of the reasons I liked that idea is that it could explain why men are, on average, stronger than women. That is, although male and female souls are, on average, equal in strength, when the souls are put in bodies the men are always as strong as they can be, whereas the women aren't, because of the body issue (which ALWAYS reduces their strength some variable amount from their soul's max capability, so that they can never be as strong as the strongest man). This would cause average female strength to become less than average male strength, without having to say that their souls are inherently weaker. That appeals to me.

Anyway ... BS's comment didn't make a distinction between male souls and female souls, so this idea seems rather unlikely, now. But maybe not totally impossible, if he wanted to reveal this info in the books, and so was deliberately vague when answering the Q&A.