Tow trucks work that way too.

Unfortunately, the First Amendment does not protect against private action, only government restraints on speech. Other mechanisms like anti-SLAPP laws might help with that, but either way that's a lot of legal effort to publish some benchmarks. Intel also operates all over the world, so they could eg. sue a Britain-based branch of some media outlet that also publishes the numbers if the laws there are more in their favor.

The license can't restrict third parties from sharing benchmarks, which is why it puts the onus on the user not to allow third parties to share them. If some news site was to publish benchmarks without disclosing the source, Intel would first have to take them to court to force them to disclose who provided said benchmarks. That's as far as I can see it directly impacting sites that don't run their own benchmarks. That said, the sites that do run their own benchmarks would be on the hook. Sadly, even if this is unenforceable, the potential legal battle to have it declared so would be scary enough to quash some criticism.

This really makes me doubt if I should buy Intel products in the future (to the extent that I have a choice). If I can't get performance information because Intel has something to hide, I'll have to look elsewhere. Really, this is sufficiently distasteful behavior to make me avoid Intel even if the products work just fine.