It changes “The Primal Self (ta)” bonus from Talent to Spell, which allows other talents to benefit.
I didn’t take it to be changing the primal self bonus, but rather, because the spell overlapped the talent so much, to instead offer an additional bonus (because they stack). You don’t lose the bonus from the talent when you cast the spell.
But other relevant talents don’t stack with primal self bonus, but do with the spell bonus.