They did something similar with the Kernel in 2011. It's not an entirely new strategy.

They stopped publishing the git tree or separate patches for the RHEL kernel and only published the tarball with no version control. At the time, Oracle started a project to reverse engineer it back into a set of unique patchsets called "RedPatch". Was kindof wild.

Not sure how long it lasted. It doesn't seem live now, though.

https://www.theregister.com/2011/03/04/red_hat_twarts_oracle...

https://www.theregister.com/2012/11/12/oracle_launches_redpa...