This will be handy for all those ex-pats living in France driving ten-year-old cars which haven't been back the UK in years.
There was slight possibility of the Gendarmerie taking an interest in an expired disc but no hope now that discs won't be displayed.
One of my Chamonix friends successfully bluffed the Swiss border guards this way. His 1999 wreck of a Punto hasn't been taxed nor tested in at least ten years. The official wanted to see papers and he just kept answering "all on computer, no papers" until they gave up.