Yes, that's no doubt true, but I'm not sure that it would matter, as the point seems to be that talent is not as magical (to use the word in the video) as it is usually taken to be. Would-be singers are particularly vulnerable to this kind of criticism. Nobody ever thought (I imagine) that somebody like Tom Brady would be where he is without training, coaching, practice, experience, etc., but we hang on to the myth that singers are different. This doesn't mean that anyone can become Tom Brady, only that it's a big mistake to cut short a goal because someone says "kid, you just don't have it."
By the way, the argument in the video is lifted from Malcolm Gladwell's great book Outliers. Gladwell calculates that every great achiever (he specifically writes of The Beatles, Bill Gates, Mozart, and Michael Jordan) puts in a minimum of 10,000 hours before they achieve greatness. The greatness of the Beatles, he argues, was forged by the experience of playing 7-8 hours a day for months at a time in Hamburg. I find the argument compelling. I highly recommend Gladwell's book for anyone interested in this topic.