I imagine that the BBC approached the zoo, as the guest on the show that day was there to plug the new 'Planet of the Apes' film. I guess they decided they needed a similar, 'real life', version of the consequences of chimps being raised by humans to fill up the programme blah blah blah. Twycross just took the opportunity to clarify that these days they are a zoo that treats its chimps as wild animals that have social needs and not as 'pop stars' staying in five star hotels!
During the 4 minute clip Sharon Redrobe clearly said; 'Molly wasn't wrong, she was of her time and certainly some of the work she was doing was world leading. Like most people, she got older, and the world has changed since, so I think we have got to be very careful that we don't criticise the past'.
Then, when questioned on the way the chimps were used in the adverts Ms Redrobe stated; 'It was certainly iconic at the time and you could say that turned some people on to seeing chimpanzees as marvellous, wonderful animals. Of course nowadays our concern would be with the use of great apes in current Hollywood movies these days I think now is inexcusable. We have to show the public that chimps are fabulous animals, but chimps need to be chimps, gorillas need to be gorillas, bonobo need to be bonobo and that's how they should be enjoyed and appreciated'. -well said IMO.
Also, they have been advertising the zoo over the radio for several months.