Its not based on a source, he is guessing and says as much.You should try to know how to back your claims with some sort of proof, here is a roundup of all the predictions he provided:
https://www.macrumors.com/guide/ming-chi-kuo/
Can you give me one example where he made 'typical nonsense prediction'? It seems he sometimes doesn't get the name of the device (iPad 5 instead of air), or the exact price point; but when it comes to design, supply, and release dates, he seems spot on.
Could he be wrong this time? Absolutely, but I doubt it
Welcome to ignore