Originally Posted by
Ryushikaze
Due to the nature of the stable time loop, no one involved in it can't not be what they are inside it. This is not the same as them 'always being one.'
Squall is foredestined to become a SeeD and also plant the idea of SeeD into Edea's mind. This does not mean he is always a SeeD. Same with Rinoa. She must always 'become' a Sorceress, but is not always one. She has always had the potential, but this is merely being a vessel for the power of Hyne.
Passing along the power of Hyne is a canon fact, both believed in universe, and given as the explanation in official extrauniversal sources.