It’s not uncommon for the App Store/Software Update to make no distinction between the final GM seed and the production version, making it say you’re already up to date if you’re running the GM seed. They’re usually close enough to production that the GM seeds can update to x.x.1 type updates.

That said I’m downloading the official release now and installing it over my GM seed install simply to get beta releases of 10.11.1 to stop showing up in my updates tab.

There is a setting to opt out of the beta track. Check out System Preferences > App Store.

I found the guide for how to do it, but there's no such button there. Oh sh*t.

https://beta.apple.com/sp/betaprogram/unenroll

Are you on public beta or developer beta? Those instructions appear to be for the public beta program. If you were using the developer beta, I expect you have to reinstall the seed configuration utility (if you don't still have it) from https://developer.apple.com/osx/download/ and use that.

have you upgraded to 10.11.1 beta? Maybe we are now permanently stuck with the beta channel.

I'm running "Version 10.11 Beta (15A278b)"

same here, no upgrade prompt

Same here - gradual roll out?

Are you on a 10.11.0 Beta or 10.11.1?

I am on 10.11.1 and haven't been notified to upgrade.