Okay, but the point stands: if she was failing to meet whatever standards they say she was, why could they not provide those metrics during this meeting? If they can't point to a contract, numbers, or previous feedback (official warnings, record of egregiously poor behavior, PIP, etc.) that indicates she was failing to perform her job duties, they have no grounds to fire her. If it was just her being fired then yeah, this would still be incredibly shitty behavior but, unfortunately, likely still legal under at-will employment laws. However, depending on how many firings "happen" to be occurring at the same time, CloudFlare could definitely have a WARN act violation on their hands. The WARN act specifically calls out this kind of thing:

For purposes of this section, in determining whether a plant closing or mass layoff has occurred or will occur, employment losses for 2 or more groups at a single site of employment, each of which is less than the minimum number of employees specified in section 2101(a)(2) or (3) of this title but which in the aggregate exceed that minimum number, and which occur within any 90-day period shall be considered to be a plant closing or mass layoff unless the employer demonstrates that the employment losses are the result of separate and distinct actions and causes and are not an attempt by the employer to evade the requirements of this chapter.

https://uscode.house.gov/view.xhtml?path=/prelim@title29/chapter23&edition=prelim