The OpenJDK Project currently hosted on Oracle's Mercurial server, could be heading to GitHub through the company's move to open up the repos by moving it over to Git-based repos.
While the standard Java moving to GitHub would afford developers more tools for automation, with Java developers working on projects outside the JDK (Java Development Kit) using GitHub having access to the familiar resources.
Albeit, Oracle already moved Java Enterprise Edition (EE) repos to GitHub, which project had been succeeded by Jakarta EE at the Eclipse Foundation, though it can still be found on GitHub.
The company's effort to examine the infrastructure for OpenJDK, Project Skara would have the repos moved to Git-based repos; and OpenJDK, which is the basis for Oracle’s edition of standard Java (Java SE), with the enterprise variant of Java could become a viable tool in the enterprise.
The decision to move OpenJDK to GitHub, however lie solely in the hand of the community, and may perhaps happen in the timeline of JDK 12 due March, 2019 or shortly afterwards.