Nothing is sold, and the extension only runs on YouTube. Firefox now asks every extension to label what it sends - for RYD that's the video ID to look up dislikes, and your likes and dislikes with a random ID. Same as it always was.
About Patreon: Premium only shows up in the raw counts panel under the video ("Hide raw counts" in the settings turns it off) and in RYD comments. If you saw a pop-up somewhere else, could you tell me what and where? It could be a bug.