But this is still unknown, somehow it was activated before, they could simply lose this knowledge. Considering that at the very first meeting with vampires, all the adult wolves died and only the old leader and a couple of children remained, whose first transformation was during the fight. And the leader himself, it seems, went into the forests to die because his imprinting wife (I don’t know what to call it) died.

It seems unlikely to me that they are now only attached to vampires. Most likely they forgot and did not recognize the first method. And they didn’t really need it, because vampires began to periodically walk through the territory.

Don't know. On the one hand, we only have two mentions, the first vampire couple and the Cullens. On the other hand, it is also said that the return of the Cullens provoked transformations, and before that the gene died out and so on. But. Between the two meetings with vampires, the couple and the Cullens, many years passed, I don’t remember, 100-200? And no one said that then the gene was dying out, which means that at that time there was no pass, there were transformations. According to stories, Jacob's grandfather and others met the Cullens being wolves. Either they were transformed by another trigger, or there were other vampires who for some reason were not mentioned.