This feels pretty unsatisfying: something that’s been “considered harmful” for three decades should be deprecated and then removed in a responsible ecosystem.
(PGP/GPG are of course hamstrung by their own decision to be a Swiss Army knife/only loosely coupled to the secure operation itself. So the even more responsible thing to do is to discard them for purposes that they can’t offer security properties for, which is the vast majority of things they get used for.)
It is, in fact, signed by the author. It's just a PKI, so you intermediate trust in the author through an authority.
This is exactly analogous to the Web PKI, where you trust CAs to identify individual websites, but the websites themselves control their keypairs. The CA's presence intermediates the trust but does not somehow imply that the CA itself does the signing for TLS traffic.
Can you provide a source this? To my understanding, the GnuPG project (and by extension PGP as an ecosystem) considers itself very much alive, even though practically speaking it’s effectively moribund and irrelevant.
(So I agree that it’s de facto dead, but that’s not the same thing as formal deprecation. The latter is what you do explicitly to responsibly move people away from something that’s not suitable for use anymore.)
I would be very much surprised if GPG has ever really achieved anything other than allowing crypto nerds to proclaim that things were encrypted or signed. Good for them I guess, but not of any practical importance, unlike SSH, TLS, 7Zip encryption, etc.
(PGP/GPG are of course hamstrung by their own decision to be a Swiss Army knife/only loosely coupled to the secure operation itself. So the even more responsible thing to do is to discard them for purposes that they can’t offer security properties for, which is the vast majority of things they get used for.)