That's what I suspect. Puts the fear of God in the employees across the entire system and shuts down any employee friendliness with union reps.
Upthread I posted a comment that the Pico Rivera store had experienced employee protests re: wages. That's now a non-issue.
The problem is that such a system-wide measure has attracted undue attention.
One or two plus a couple of decoy stores in a region would work over time, but this might not.