any legal entity can register their integrity attestation keys, with oversight by a bureaucracy in a process that takes 6 months and €100,000
That wouldn't be great, but at the same time an improvement over the current situation.
attestation key that leaks into open circulation (such as FOSS) will be blacklisted in the registry because it no longer attests anything
Which makes sense if remote attestation is what you want.
Yes. It makes sense for well-regulated remote attestation. But is that what we actually want or do we want to destroy the concept altogether?