I doubt this is LH going after people who they think are abusing the benefits, I believe it is more about process simplification/improvement/control.

In the past few years, access to the benefits offered by your shiny cards is no longer based on showing your card to a person, instead you gain access by scanning your boarding pass (which has the relevant FF number entered). This only works if the system has your correct FF number with the status allowing the benefit.

If LH was just looking to crack down on A3 *G flyers there are lots of easier and more effective ways of doing it!