Hello @Scott M Decker, welcome back!
Sonos wants to update to 90.0-67171.
Has anyone still on S1 applied this update? Any benefit or detriment to updating?
Sonos S1 systems should not be able to receive this update. Sounds like the Sonos App has detected an S2 system or a Sonos product that is capable to be updated to the latest Sonos App version (S2).
If you’ve purchased any S2-capable Sonos products, you might need to power them off temporarily and then Reset the Sonos app and reconnect to your Sonos S1 App.
Let us know if the above helped and if you’ve had something changed in regards to your Sonos system.