I would agree with that more than what the posted article wants to tell us, but I'm not sure that holding them from the belly up from the time they are small kittens is the whole secret of cat training.
It's been known for a long time that cats are quite trainable in terms of following human commands. You can see that in old films as far back as the 1930s where cats are obviously doing exactly as they are told as the camera zooms in on them. I'd assume that a very skillful (and well paid) human trainer was required to get the cat to do what was supposed to be done, but the point is that certain cats are capable of being "movie stars" with professional human assistance.
https://www.youtube.com/watch?v=31l0c9aQhKo
cats are super intelligent.
they CAN do almost anything... any kind of trick or task
they are just too smart to let lower species (like humans) tell them what to do, is all
https://www.youtube.com/watch?v=31l0c9aQhKo
Our two respond and know their names and that of the other, sometimes come when called (if they're in the mood) and are overall the sweetest additions to our lives. We love them very much.