The statement does not make the biggest sense. The subclasses of the classes which have to pick a subclass at lvl 1 are locked when you recruit them, but you can respecc in any case, so doesn't really matter. Um, ...
Every class is locked before you meet Withers, so probably before you get lvl 2, because Withers offers the respecc. So Astarion and Gale are equally locked first if concerning the class. The subclass of both comes at lvl 3, so you can choose it, but after you hit the Accept button their subclasses would also be locked before you met Withers, and you had to reload to change again. Such a lock does not interest me. I interpret Swen the way that the lock is only temporary and without importance.
Which is bad because while an impossibility to change the subclass would help me, the just deferred respecc does not, in my decision wether to change and to what.
