I have often noticed in the past such 'policies' of many (other than swiss) carriers on some airports all over the world - but I have never encountered any strict policy to finally only allow passengers to board with such tagged carry-on luggage.

The policy would be difficult to be enforced 100% (if I check in the night before my flight, or for connecting flights coming from other airlines).

If I am afraid of that rule (example BA at LHR always controlled the weight of my carry-on luggage), I simply will not show it (the carry on luggage) when I check-in - and I never had any difficulties when boarding (without tags).