[aordano]

Beyond this particular case, it happened something similar to me and other people i know (using burner chips, mainly); after a while of not paying the bill/adding credit to your line, the companies here cut the service and repurpose the number to sell again to a new person. This process, though, does not disable WhatsApp nor its backups if you already had a session open, so when you download WhatsApp to create your account with your "brand new" number, it instead logins to the account created before.

Then, it autodownloads all the data, keep chatting with their contacts, and everything you would normally do when you migrate an existing account to a new phone.

I fathom this is responsibility of the telcos that reuse the numbers, but it seems is already an established practice and apparently there is no procedure to disclose to most common services that the number is dead.

I thought something like that was going on, and even more reasons to move on from SMS/phone auth.