I assume they are removing cars and buses making use of this tech first as they are far more likely to be dirty that cars. Even the cheating VW cars were still magnitudes cleaner than the immediate previous generation.
I think they are going to find their pollution problem is nearly as bad and will need to make more difficult choices rather than relying on fear of a partial truth. It isn't just diesel cars making their cities dirty. As stated, the change made to even the cheating cars would have demonstrated such if it were just cars
Buses, HGV's and all other large vehicles actually tend to run okay on diesel, because they are large and expensive enough to carry and pay for the necessary equipment to reduce NOx and PM. It's small cars in particular where diesel just doesn't work.
I think they are going to find their pollution problem is nearly as bad and will need to make more difficult choices rather than relying on fear of a partial truth. It isn't just diesel cars making their cities dirty. As stated, the change made to even the cheating cars would have demonstrated such if it were just cars