AFAICT all problems come from the Launcher classes, which includes com.google.api.services.compute.model.Operation and the referenced chain of classes. But maybe there are other entries as well. It should be relatively easy to write a unit test and to capture at least some missing classes, but things like JacksonFactory worry me a lot.
The entire idea to Serialize Cloud agents to disk is a bit questionable, but there is some logic dependent on it.
Note that Google OAuth plugin is also affected by JEP-200 (
JENKINS-50216). Without it this plugin cannot work AFAICT, at least in some cases.