my opera browser just updated again and I have no release notes or changelog to read as the above forum links are incorrect. is anyone going to fix this?
That forum post is probably no longer updated, or only updated for major changes or new features. These type of patch updates only update base chromium version or just apply a quick patch. (i.e bug fixes or security fixes)
opera://update/ page checks for updates if you are running an Opera or Opera based OperaGX browser.
https://ftp.opera.com/ftp/pub/opera_gx/ lists all OperaGX versions with their downloads. The last entry will be the latest available version. (currently 72.0.3815.473)