Another similar tracking vector that lets any app detect all installed apps by using android.intent.action.MAIN Query: https://support.google.com/googleplay/android-developer/thre... without the QUERY_ALL_PACKAGES permission.
No response from Google. Being used by dozens of apps in the wild.
Edit: Original Research link: https://peabee.substack.com/p/everyone-knows-what-apps-you-u... (HN: https://news.ycombinator.com/item?id=43518866 , 482 comments)