With macOS 10.14.5 and macOS 10.15 Catalina, Apple has mandated notarization of all applications. Conforming to this requirement, October 2019 updates for both Adobe Acrobat and Adobe Acrobat Reader applications on DC and 2017 tracks are notarized.
Adobe recommends that third-party plug-in developers should get their plug-ins notarized by Apple. Without notarization, your plug-ins will fail to load in Adobe Acrobat and Adobe Acrobat Reader on macOS 10.14.5 and above.
For more information on the Apple Notarization process, see Notarizing Your App Before Distribution.