I wouldn't infer that the person is a low performer. However, I do think it's fairly likely they were either unknown at the VP level or not viewed as worth figh

I wouldn't infer that the person is a low performer. However, I do think it's fairly likely they were either unknown at the VP level or not viewed as worth fighting to keep by VPs. Large layoffs are typically discussed and orchestrated only at the highest levels of management, so if you're an IC if you want to be protected you need to be on the radar of your boss's boss's boss's boss (or something like that). And I think you're right that someone who sat at L5/L6 for 15+ years wouldn't be a stand out at that level by any stretch.