Interestingly, the reference implementation does seem to reference FairPlay, which is very much a copy prevention/anti-circumvention system (used for iTunes content, but also video encryption via HTML EME): https://github.com/JJTech0130/pypush/blob/main/albert.py

Assuming that DMCA does not cover API authentication (i.e. preventing unauthorized third-party clients from being able to access a server-side API – and I really don't know if it does or doesn't!), I wonder what the implications are if the same mechanism is used for both DMCA-covered DRM mechanisms, but also non-covered other purposes.

My intuition would be that it can't be good to "multi-purpose" a DRM tool from a DMCA enforcement point of view, but maybe that was never Apple's plan, and they just used the most secure attestation technology they had available on each platform, which for Intel Macs might just have been software-only FairPlay.