Due to the GPL, eventually all commits will find their way into the OpenJDK repos, it is sort of similar to how vulnerabilities are handled — with paid support,

Due to the GPL, eventually all commits will find their way into the OpenJDK repos, it is sort of similar to how vulnerabilities are handled — with paid support, you will be the first to get updates. Also, since Oracle does most of the development on the main branch as is, they have deep understanding of those patches - while during backporting it may not be as expertly implemented. But Oracle also backports commits to older JDKs, e.g. Java 8 is supported for 2030, though that is paid. The main takeaway is that it is still a singular project where bugfixes definitely, but even most custom features find their way eventually back to mainline (e.g. it was the case that Microsoft made some specific feature for their usecase, that was later merged).