I think she may have been making things up - I had never come across this sort of RSPCA guideline (and it's certainly not a law!) when I was more actively volunteering there and reading through their literature (guidelines on treatment of dogs, cats, horses, cows, pigs, ducks, chickens...you name it!!).
If you're doing everything else with the dog, it shouldn't give the dog enough time to realise that destruction is a good way to alleviate boredom! And a dog that isn't resented by its owners is going to live a very happy life