I thought the only client allowed on Signal was the official build provided by Signal itself? Does this mean Signal does officially allow another build (Telemark's TM SGNL) access to the Signal network?
There was a case where a teenager in India rose to news media popularity by publishing a messaging app, which was a simple rebranding of Signal he made using some other tool which patches assets iirc.
It was blocked by Signal, but only after reports surfacing about it being an insecure rebrand.
I don't think they asked Signal Foundation for permission, they just did it. Just because you're an Israeli government contractor doesn't mean you can't get rich from piracy and modding so long as you find gullible buyers
Also, how would Signal know this isn't the official app that's accessing their network? They do have a standing policy against it but if someone copy-pastes the APK and makes modifications in parts that don't talk to your server, how's your server to know that an illegitimate client is talking to it