Your comments sound pretty damning and got me curious if there was some conspiracy I didn't yet know about, but then I click to the source and it turns out that this is not a silent change to upload more data without users knowing anything, it's an announced feature to (afaik optionally) backup this data to Signal's servers, protected with a PIN. It may not be obvious to my mother, sure, but it's also not exactly rocket science that 4 digits will not be secure under any offline-attackable circumstances. (For that they add SGX which seems broken so that is moot.)

On the other hand, it's not exactly hard to find out who's talking to whom if the server owners want to (or are forced to). Traffic analysis without onion routing is trivial at least in theory, so tptacek isn't quite correct either that Signal does not allow any sort of social graph obtaining. Sealed sender helps a little, but is not a solid thing to rely on if you're the kind of target for whom they would even bother submitting a subpoena. Wire also doesn't keep a list of who's in a group with whom (your client handles that) so there, too, you have to do traffic analysis to find these relations -- just an easier form than you would have to do if Wire would have had sealed sender.

Hence I consider it all about equal, with a small asterisk for Signal that they try really hard to make it as good as possible (compared to Wire doing just the now-regular end-to-end encryption).