Forgive my sloppy phrasing, I should be clear: Oracle's license terms prohibit public disclosure of any benchmarks without their consent.

So technically you can benchmark in-house, but you can't publish those results without written permission.

That's a lot worse. It's not just prohibition, it's a way to filter out anything negative through license enforcement.

Yes. SQL Server and others used to have the same terms but was later removed.

The original intent was to prevent non-neutral third-party benchmarking by biased agents that sought to discredit their products through contrived setups (which admittedly can be a problem for any product), but to enforce it through licensing seems a bit heavy handed. Oracle does allow benchmarks that are favorable to them (see TPC-C benchmarks).