I wonder how iCloud shutdown would affect this route, but: your Passkeys are synced to your devices locally, and the whole "scan QR code on another device with

I wonder how iCloud shutdown would affect this route, but: your Passkeys are synced to your devices locally, and the whole "scan QR code on another device with your phone to authenticate" flow is fully local, utilizing key authentication over BLE. Theoretically, your Passkeys should still be on your iPhone/iPad/Mac/iThing, and QR authentication will work. (And then you provision another key on another device, since Passkeys' intention is like SSH keys, allowing multiple on a single account)