This is smart politics. Rather than simply telling people FB is a monopoly, she runs a limited experiment that had it been left alone, would have limited effect since the budget was so small ($100). Now this puts FB in a bind. If they really are a middleman for content, then these ads don't violate any laws and shouldn't be blocked. However, FB as a company with a product should block it just like coffee shop wouldn't allow a banner on the wall saying "better coffee down the street".

This sort of overreaction to a small calculated provocation just proves the point that FB is a company first, platform second. This was obvious already to many people, but now there's a clear illustration that'll make it harder for FB to simply say they are a neutral platform.