There's of course equivalent security processors and domains on pretty much every ARM application soc, but the exact semantics of them (like pretty much everything in the ARM space that's outside of the actual CPU core complexes) is extremely heterogeneous. They might even be running in EL3 on the application cores themselves. Wrangling all of that is probably out of scope for W11 RTM.
Going off on a tangent here, but thinking of how most of the world ran Windows XP/Windows 7 on cracked versions, would it be possible that following the TPM requirement, someone would write a TPM emulator (or maybe some more clever hack) so that Windows 11 doesn't complain about those stuffs and just install/boot? (disclaimer: I have no idea how TPM works and have never had to use it...)
Emulating a TPM at the hardware level is possible but too much work when you can just buy the chips themselves--they aren't some magic unobtanium locked down thing, for example: https://www.digikey.com/catalog/en/partgroup/trusted-platfor...
The problem is to get an old system to use it you'd have to also modify its bios to make it aware of the TPM (and figure out how to get access to the phsyical bus the TPM needs to interface with the motherboard). There is a lot of reverse engineering and work to do that sort of thing.
good for us that amd does it for free, huh? https://www.amd.com/en/technologies/pro-security (fTPM)