In Terminal, run sftool resetbtm, authenticate if needed, and reboot.
Also trying to reset the state of "Login Items Added by Apps", and I tried this, but said that the command wasn't found. Is that an issue in the first beta, perhaps?
If it helps, my context is different to the OP – I'm looking to move an login item previously installed using SMLoginItemSetEnabled to SMAppService, and I'd like to test resetting the state of the permission notification.