Must be some setting on your end then that’s different than mine. When I install a content using the content manager. It syncs with my cloud profile. So whenever I manually delete a content folder from the Official folder. When I log into the sim again, the content manager will automatically checks with my cloud profile and when it finds there’s a missing content from the official folders it automatically redownload the missing content.
So the only way for me to actually delete the marketplace contents are through the content manager. Select the content, delete it through the content manager, and the sim will sync my cloud profile that I have uninstall and content.
So the next time I sign in to MSFS again, it knows that I have sent an uninstallation command before, so it doesn’t redownload the missing content for me.