This article was a fascinatingly uneducated take on what it means to learn music mixed in with a classic dose of American "my child is better than you." Like many piano students who started early, I too played some easy Chopin music at ~6, and I bet most later starters also play some Chopin within 1-2 years of starting (in fact, I bet they reach the Chopin sooner).
Perfect pitch is very much not required to be a professional musician, and seems to help only in a few areas, and only by accelerating your musical education a bit. I'm sure it makes things like the Suzuki method easier for young children, but you arguably shouldn't use the Suzuki method to teach music to your kids anyway since it tends to guide them to a local maximum by emphasizing ear training over reading. Learning pieces by listening rather than reading works for easy pieces, but I bet nobody has learned the Hammerklavier Sonata or a Paganini Caprice by ear.
I really wish the idea of "racing" through your musical education with hacks like this would stop - the only real way to get to advanced levels quickly is with a shit load of practice. My friends who went to international competitions at 18-20 were all practicing 5+ hours a day by age 12, and several of them actually started their music education at age 7-9 rather than obscenely early like this.