This is because as some current Windows 10 users are finding out, one of the “hidden” requirements of Windows 11 is having TPM 2.0 enabled on their computers. The reason why Intel Macs will not be officially supported is because Apple has never offered support for TPM 2.0, so if you were to run the tool that checks compatibility, you will be greeted by a message saying your computer can’t run Windows 11.
It is possible that Apple could release a firmware update to enable TPM 2.0 support, but the question is, why would they? It is clear that moving forwards with their Apple Silicon chipsets that Apple wants to further reinforce their own ecosystem. At the moment due to the fact that Microsoft doesn’t sell the ARM version of Windows 10 to consumers, you can’t even run Windows on Apple’s M1-powered computers.
Perhaps you could use some kind of virtual machine to run Windows 11 in the future on an Intel Mac, but if you were hoping for official Boot Camp support, that seems unlikely.