Yep. It's complete bullshit and it's a shame to see cowardice corporate legal fearmongering like this in a company like Google, that was once at the same wavelength as the technical/hacker community. As if Firefox, Microsoft or Apple would sue them for publishing one browser benchmark.
Even worse if it were a pretext to not make Chrome look bad.
"Legal concerns" is a weird excuse, but personally, I'm glad they didn't name names. The point of this article isn't to shame any browser vendors, it's to talk about WebAssembly. Naming the browsers would have just distracted from the article's topic.