China's WeChat certainly wouldn't like this yet there's a modified build of that as well, according to the article.

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