There is some debate as to how much Hwang Kee could have actually gotten out of a book. Some claim he had to have had some instruction of karate. There is also some debate on whether or not Hwang Kee trained at the Chung Do Kwan under Won Kuk Lee, he might have picked Suparinpei up there if he actually did know it, however seeing how its a higher level form, Won Kuk Lee probably didn't know it. In all honesty its probably not true. Most TSD stops at Sip Soo, which I'm guessing a book would probably stop there too. If these higher level forms escaped Shotokan, then there's no way they'd make it to TSD.