I wonder whether it's already started in Brussels. I flew out from LGW on Thurs - Business on SN Brussels (and had to have a cabin tag on both my laptop and small carry on bag) This has been in place for some time now. When I flew back from BRU on Friday in Business, SN insisted on weighing both pieces individually and putting proper barcoded tags on both items. When I challenged them and asked was I going to have them taken off me at the gate I was told no, it was simply to check the weight.
Absolute bolxxxks - as usual, when I got to the aircraft there were already handluggage bags (i.e. small enough for normal planes, but not the tiny SN planes) sitting by the exit door for the hold. My colleague didn't have space for his bag and surprise, surprise it was taken off him on the plane - with a "don't worry" it's been properly tagged for the hold comment. How convenient.
I appreciate this appears to be an airline rather than airport policy - but I think all roads point to a slippery slope of if you want more than a clean pair of pants and a toothbrush, it's going to go in the hold.