I could be wrong but even though TPM 2.0 and secure boot can be turned on in the BIOS in 100 and 200 series boards I'm beginning to think that VBS and Kernal DMA protection may be a determining factor. Whilst any PC with a 64 bit CPU and sufficient RAM and drive space may run win11 with no problems it may not be able to run it securely which I think is what MS is going for this time round with TPM and secure boot and I think 300 series and up support Kernel DMA protection which I think is why MS went for the 8th gen and up or similar for AMD. As I see it at the moment, 100 and 200 series boards will most likely need a bios update which is currently being worked on my most hardware manufacturers to address this. Until we know more though everything is up for speculation.
the problem is that some 100 series boards like Asus Z170 do NOT include the Intel PTT (built in TPM) option in the BIOS and Asus has not issued any new bios updates for those specific boards to enable that option. so those users are totally screwed
for 200 series boards like Z270, there are already new BIOS updates available for most of those boards