Google says "Did you mean: tpm and secure boot?"

I wouldn't update an old machine to Win 11 if it lacked 'necessary' hardware features - except in play. MS could release an update which requires these features at any time. Requiring biometric authentication, perhaps. Maybe in 2025 when Win 10 stops being updated.

Kasperski was warning the other day of fake Win 11 updates. Presumably, unlike the eventual production updates, these are unsigned. MS might use features of TPM v2 to stop that once Win 11 is released.

I hope that manufacturers continue to sell machines on which you can turn secure boot off, or at least run a non-Microsoft OS. It's cheaper to buy a Lenovo PC with Windows installed and overwrite it with Linux than buying a PC with no OS.