If it is a different key, wouldn't there be a "keys have changed" notification in my friend's chat window when I add a new whatsapp-web login? If the keys haven't changed whatsapp-web must be capable of decryption of messages meant for my device, no?

edit: Is there documentation somewhere? Makes no sense to me that my friend is encrypting with the same public key (before, during, and after whatsapp-web is provisioned), but somehow it is decrypted on a new device with a different key