The notarization process is supposed to mean that if it notarizes then Catalina's gatekeeper will happily allow it. There's no guarantee that you don't have a crasher bug, of course, but if it runs on Mojave it will probably be OK on Catalina.
Before finding the page on the gnome wiki my first notarization attempt failed that way: the process reaches the end also if the libraries are not signed (I thought the --deep flag was enough to sign them all), but the program fails at runtime to load a .dylib without signature.
BTW: I've upgraded a machine to Catalina and tried the build (that I made on another machine), everything seems to work, without any specific entitlement.
