Sorry, I forgot to follow up. Since my extension was tiny and I made it as a hobby project, I submitted links to “placeholder pages” I made on my website: https://cwpat.me/delfruitinfo/privacy and https://cwpat.me/delfruitinfo/eula , which just say “TODO: privacty policy for X twitch extension” and have a link to this forum post. And my extension was approved. (here’s a link to my extension: https://www.twitch.tv/ext/tirqrgy7bg0rz4sgyiciy1x8uu4cwh-0.2.0)
This was right after extensions were released though, so Twitch may have changed their policy on this stuff.