Not exactly. Yes, revealing the combination requires the person to implicitly admit that they know the what the combination is. But if the government can prove that they already know this "testimony" -- which they can in most cases -- then the "foregone conclusion" doctrine applies and the 5th Amendment privilege cannot be asserted. See, for example, the Massachusetts Supreme Court's decision in Commonwealth v. Jones. [1]
There is also conflicting 11th Circuit precedent that further requires the government to establish with "reasonable particularity" what is on the encrypted device. [2] In my opinion this is not correct; the contents of the drive have nothing to do with the testimonial value of the combination. In any event, this issue will eventually need to be resolved at the Supreme Court.
> I think it is unreasonable because it's asking companies to willfully violate their user's privacy and trust, and to severely undermine encryption as a whole. There is zero chance that this does not get abused.
I don't see how it violates user privacy or trust. In general, you don't have the right to keep records secure from law enforcement if they have a warrant. If this law is passed, these companies should simply disclose to their customers that they will provide law enforcement with the means to decrypt their data, as many already do.
I also don't see how it severely undermines encryption. Yes, end-to-end encryption is more secure, but it's not the industry norm. Security is relative, but I wouldn't call Gmail "insecure" just because Google allows law enforcement to read emails with a warrant.
[1] https://www.socialaw.com/services/slip-opinions/slip-opinion...