MacOS 13 Ventura and iMac Late 2015

AppStore says MacOS 13 (Ventura) will work with my iMac and the App Store download button is available.

However my understanding was that my OS (MacOS 12.7.6, Monterey) was to be the last OS update my iMac (Late 2015, iMac17,1) was going to get. In ‘System Preferences’, the ‘Check for Updates’ button says “Your Mac is up to date - macOS Monterey 12.7.6”.

Has Apple actually changed its mind about this?