Did the Alpha Kids had a session before the scratch, or did they exactly start to exist when the beta kids scratched?

Now this is hard to explain due to temporal mechanics. But, the Alpha Kids did not exist as the Alpha Kids until after the scratch, but they also landed 13 years before the scratch.  It’s similar in the way the a player’s planet doesn’t exist until they enter but the planet has existed for ages.  Essentially, a long amount of time was compressed into a short amount of time.