I am assuming, based on the fact that it's a project by an American company, that this is largely being done by functionally monolingual English speakers. I wouldn't want them to attempt to speak for other cultures. And I wouldn't want to shame them for not attempting to speak for others.

It's a bit unfortunate that they use the word "human" so expansively when the scope is so limited, it's true. But it's a new project, so let's give them the benefit of the doubt and assume that that's meant to reflect the project's aspirations. Even if the reality, after only a few short months, doesn't quite achieve it. Tech culture is supposed to value iteration, and accept that things won't necessarily get it all right on the very first try.

A more constructive way to make sure other cultures are reflected would be to say, "Hey, this is a great idea. But looks like you're only covering Anglophone sources right now. Can we help by contributing additional sources?"