"This car is the fastest one on the planet, but we legally forbid you from talking about how fast it can go."
Sure.
Sure.
It's possible, even probable, they look at your results and then give you permission to publish.
As long as they do not refuse permission or delay giving you an answer indefinitely, asking you to contact them first before publishing is arguably a reasonable requirement.
Which makes observable results inherently biased and any comparison useless.
And even if all they do is filter out actually crappy benchmarks - other db providers (like postgres or mysql) don't do that - so the comparison still isn't fair.
It's like you had 2 candidates for a job and phoned their previous bosses, but candidate A forced you to only phone guys he approves of.