Quarantine != Gatekeeper. They are two different things, stop conflating them. Even with a signed app, you’ll get the quarantine dialog. See this Apple Support

Quarantine != Gatekeeper. They are two different things, stop conflating them. Even with a signed app, you’ll get the quarantine dialog. See this Apple Support page for confirmation and to see an example: https://support.apple.com/en-us/HT201940 https://support.apple.com/en-us/HT201940