That's not how it plays out in reality. usually nothing gets done because "upgrade this package" is never on anyone's priority list. Or teams end up doing shit like JAR shading or forking and renaming a package with some _v2 or whatever suffix to be able to support both the old and new version simultaneously in the main code base. And then of course nobody ever updates the runtime (hello, enterprise monoliths still running on Java 6/7!) It ends up being a complete mess.