Although I didn’t see the programme, I had heard about this particular element of the show. Methinks they were trying to be a mite controversial.
It is true that about 25 years ago, Airfix did sanitise a lot of their box art. Partly this was to do with being a bit more careful about what they were depicting but there was also a general tightening up of what could be displayed from an “accuracy of depiction of contents” point of view. By 1981/82, Airfix and most other kit manufacturers had got rid of their box art completely and were showing less than inspirational photos of made up models on the box lids.
The good news is that for the past ten years, Airfix have gradually reintroduced a lot of the original artwork and commissioned a lot of new stuff as well. You might be pleased to know that their current boxing of the 1/72 scale Lancaster shows the same picture that adorned the Lanc box back in the 60s i.e. the plane coming in over the black and white chequered hut at the end of the runway with one of its engines streaming flames and smoke. Very dramatic.
So, May was sort-of correct but really out of date.
The one genuine PC element of modern kit selling is the lack of Swastikas shown on Luftwaffe kit boxes or included in the enclose decal sheets. Did they mention that?