I guess it’s from the PDF++ plugin (sorry if I’m wrong). So those who don’t use PDF++ will not receive such notification.
Other than installers, if you’re a PDF++ user, make sure it is up-to-date, because I (PDF++ dev) have made many updates to ensure PDF++ will keep working with Obsidian 1.8 since the day after the first insider release.
Generally speaking, if you encounter any issues, updating everything (plugins, themes, app & installer) is the very first thing that you should try, as suggested by the Troubleshooting Guide.