We do plan to support other admin databases in future releases, so we keep all of the scripts (SQL Server, Oracle, etc) in sync. That way we can have them available for testing on all platforms. These other databases are not currently tested or supported though and there is no ETA set right now for when they will be.
If you are looking to use one of these other database types for the admin database, I recommend that you open an Idea on the Community. Ideas here are reviewed by the Product Management(PM) team for potential inclusion in a future release of the product. Other customers can vote and comment on these Ideas to let the PM team know they are interested in this feature as well. The PM team will update Ideas here once they have been reviewed to let everyone know if they have been rejected, accepted or wait-listed.