At ABQ, I received the random beep at a WTMD in the precheck line and was told to empty my pockets and go through the body scanner. I opted out and received a pat-down. I have read reports of this happening at PDX as well.
I asked the TSO giving the pat-down why this did not result in a hand swab ad he told me that this was the new procedure. He told me that it should be the new procedure for everywhere now. I feel like this procedure is a bait and switch for the people who paid 85 dollars to avoid the body scanners then being told that they have to go through them sometimes.
My issue with people setting off the WTMD not being given another chance is that sometimes, the TSO yells at people that they need to keep their belt, shoes, etc. on. At one instance that I encountered, a concern was raised about a belt potentially setting off the WTMD and the TSO told the passenger to try to go through and see if it did at first. I could see there being cases where the TSO tells people to leave belts on which set off the WTMD and result in the passenger being sent through the body scanner.