The ZGenerational flag was obsoleted in JDK 24 as part of removing the non-generational mode of ZGC in JEP 490. The flag was still obsolete in JDK 25, which is a LTS version, so that user's that might specify/try to use it are prompted with a warning. Now that we're past JDK 25, the flag should be expired. Likewise, the ZMarkStackSpaceLimit flag was obsoleted in JDK 25 and can now be expired in JDK 26.