Microsoft won't offer Win11 via Windows Update if your device doesn't meet the hardware qualifications they've set for the OS. If the CPU is the only thing that doesn't pass the test, you'll still [allegedly] be able to install or upgrade to Win11 using the ISO. This stuff is tentative because we won't have the official release ISOs until October 5th. If the device is not secure boot capable [it doesn't have to be enabled - So Far], or doesn't have TPM, setup using the current ISOs will not allow you to proceed. There are hacks to get around that, but now there's an easier way.
The 1st is a script you run. Note that the GitHub page where you download it might be confusing -- click the "Download ZIP" button on the upper right when the page opens, and the script will be included in the downloaded Zip file, along with the much larger script to download Windows ISOs. I was interested in seeing if it enabled new builds in my unqualified Insider VM, but there haven't been any in the Beta channel since Microsoft allegedly flipped the switch to stop updates to unqualified installs.
bleepingcomputer[.]com/news/microsoft/new-windows-11-install-script-bypasses-tpm-system-requirements/
The 2nd tool comes from EaseUS [they used to be a regular GOTD contributor]. Their free tool lets you download a Win11 ISO, and with a button to "Bypass TPM 2...", likely modifies that ISO to remove compliance checking during setup.
neowin[.]net/news/easeus-win11builder-15/