Facebook/Meta (the owners of Instagram) have been extorting phone numbers and IDs from people for years. They don't target everyone all at once, but a few hundred here, a few hundred there. I don't know if they do it for all new accounts, but the practice is definitely not new.
This is one of the many reasons why I stopped using their services.
It's been happening for a few months, my theory was that in the runup to the election it was their only idea for CYA about bots, and it just so happens to mean they're using facial recognition scanning to catalog the real humans on their platform.