That book argues that mass media are biased because they are beholden to for-profit corporations, advertisers, and large-entity sourcing. I didn't read it, that's just in the outline that's in the link you provided.

I think Noam would prefer if they were government mouthpieces instead of corporate mouthpieces, as he's socialist.

Regardless, I don't think "Noam Chomsky wrote a book" is an argument with evidence. It's rather an appeal to authority. But if it were, the book should actually be about the argument you're making.