She’s not trying to talk her way out of getting laid off. She’s forcing them to justify it as a firing, instead of calling it a layoff. Because if you get fired with cause, you don’t get unemployment insurance. But if you get laid off without cause, you get unemployment. If she can get them to slip and admit that there’s not a reason for her layoff, then she can take that to the unemployment appeal and prove she deserves to claim insurance.
It could also affect her going forwards, because it determines whether or not she’s able to use her manager/coworkers as a reference in the future. If a future employer calls her manager and asks “would you hire this employee again” and she was fired for underperformance, the answer will be “no”. But if she was laid off without cause despite hitting all of her metrics, the answer will be “yes”. So it’s advocating for her future employment prospects, by not allowing the company to falsely blame her performance for the firing.