The headline shortchanges the exception.
These amendments redefine the term “operating system provider” to exclude any person or entity that distributes an OS or application “under license terms that permit a recipient to copy, redistribute, and modify the software.” Any software distributed under the GPL, MIT, BSD, and Apache licenses satisfies that test, which removes the likes of Debian, Fedora, Ubuntu, Arch, and the BSD family from AB 1856’s scope.
This ahould mean an Open Source, encrypted Discord competitor would also not be required to do age checks (i.e. Matrix, etc).