Definitely, but that's a result of compressing (with any algorithm) past a bitrate that would allow detail to be retained with high frequency details including

Definitely, but that's a result of compressing (with any algorithm) past a bitrate that would allow detail to be retained with high frequency details including noise being the first to go, not the result of noise having signal as was stated and more importantly unrelated to film grain synthesis which is about adding something new on the output side.