there's a definite step change in COMPANY POLICY here.
It used to be "darn, everyone has turned up, what shall we do, we've entered into a paid contract, we need to convince someone to leave"
now it's
"We'll randomly pick people and kick them off the plane, yes "sir", that's not a euphemism, it could happen, I suggest you leave before we legally assault you"
What is of concern is its COMPANY POLICY to do this now, as confirmed in the email above.
"What? You're flying home to your mother's funeral, sorry "sir", company policy you see, right, someone assault him, quickly, we've not got time to waste"
Your seat is no longer your seat, they used to have to buy it back off you. They can now deplane you because they feel like it, through no fault of your own, is that really of no concern to people who choose to fly with them. It would concern me. Won't concern the sheeple, their planes are still overbooked today.