@delta i don't even believe WA's e2e encryption is real. When you reactivate whatsapp from a new phone, without the transfer protocol, but from the same number, you can see the plaintext of all messages you missed. If the key was in your "end" (old phone) only, there would be no possible way to see those messages. Whereas for Signal if you don't explicitly back up and transfer keys, you won't be able to decrypt messages your received in the meantime.