Forgive a non cryptographers naieve question, but isn't the whole point the third party acts as a cut out so the only role of government is to warrant the KYC 100pts has been met, not in what context the question is being asked?
Ie, it explicitly doesn't trust government to "not do the bad thing" by hiding the information from them.
Apologies if I misunderstood your question, but I suspect it doesn't matter because the answer would be the same in any event.
This whole discussion for me is a bit like hearing that my child is safe at the kindergarten because the male staff promise to always use condoms.
The relative safety of various cryptographic approaches (or fancy protocols) is irrelevant when the fundamental problem is that it is deeply suspicious that the government keeps trying to insert themselves into my private life. In my crude analogy, they'd be a registered sex offender working in child care.
Any such repeated attempt at spying on the public, blocking opposing political voices, silencing journalists, or anything at all that even smells like those things must be vehemently opposed. Platitudes and assurances can never be enough from a government with a history of abusing this kind of power.
Ie, it explicitly doesn't trust government to "not do the bad thing" by hiding the information from them.