currently, we recommend users installing to Mac OS bypass Gatekeeper by going to the security preference pane and overriding the warning given by the OS whenever opening an app for the first time unless it came from the apple app store.
My understanding is that after the deadline users will no longer be able to override these warnings.
"As a reminder, Mac software distributed outside the Mac App Store must be notarized by Apple in order to run on macOS Catalina."
"In September, we temporarily adjusted the notarization prerequisites to make this transition easier and to protect users on macOS Catalina who continue to use older versions of software. Starting February 3, 2020, all submitted software must meet the original notarization prerequisites."