Comment by _heimdall
Again I am no expert here, this is just my understanding after being in the industry for a couple decades.
As far as I'm aware, there's a fine line between layoffs or reductions in force and firing for poor performance. Its legal to cut an entire division, or to cut some percentage of a division's head count and come up with some way of distributing it across the org. It is not legal to find your worst performers, fire them all at once, and call it a layoff.
Happy to be wrong here though, just trying to be clear with the line as I understand it. Someone coming by may know for sure.
Every single employee can be fired for any reason that is not a protected class. All professionals are hired at will.