You can still install windows 11 straight from an image and it’ll ignore the processor and TPM requirements - they’re considered ‘soft’ requirements even if Microsoft doesn’t say so outright. I currently have it running on my desktop with an i7-6700k and my laptop as well with an even older i7 and TPM 1.2.

You’re absolutely correct in that they ‘drew a line’. They have a specific set of guidelines[0,1] they want CPUs to meet going forward, and it’s more of a matter of ceremony and certification rather than anything concrete nor technical.

0. https://docs.microsoft.com/en-us/windows-hardware/design/com...

1. https://docs.microsoft.com/en-us/windows-hardware/drivers/de...