My prediction is that Apple will start to use attestation (device check) to lock down iMessage. The problem is that this would require a software update for older devices.
> Warning: In order to generate the “validation data”, pieces of information about the device such as its serial number, model, and disk UUID are used. This means that not all validation data can be treated equivalently: just like with Hackintoshes, the account age and “score” determine if an invalid serial can be used, or if you get the “customer code” error.
The "customer code" error is a prompt from Apple, basically an attestation failure -- you have to contact Apple Support to get your Apple ID unlocked once you've tripped the failure. Legitimate customers will breeze right through (eg, just approving your login from your legit device), but Hackintosh users use crafty means to fake their way through the process.[1]
[1]https://old.reddit.com/r/hackintosh/comments/gij9rt/getting_...
you'd need the key from the TPM/secure enclave too, which is much much harder to extract
Apple aren't going to allow one phone to attest 5000 new iMessage clients
iCloud Activation Lock, on non-cellular devices (eg, Wi-Fi only iPads), relies on the device's serial number, Wi-Fi MAC, and Bluetooth MAC addresses as the three identifiers required to clear the Activation Lock check. Via special debug cables (eg, a "DCSD cable") there are ways to write in new SysCfg data to the flash to change those variables. This can also be done to Apple Watches (pre-Series 6) with a special dock also sold on the Chinese market.
You can (sort of easily) get your hands on a "clean" serial/MACs set for under $10-15 or so on the market.
> unrecoverable without an electron microscope and nation-state level resources (and even then, it would be extremely difficult if not impossible on modern process nodes).
Oh, so you can. It's only a matter of time.
which is exactly what happens