The "forward looking statements" protects these sorts of predictions. You only have to look at the statements about Russia, Israel and Germany, as well as the timeline provided to see that not everything in the letter and earlier statements is coming out as predicted.
I don't doubt that PK WASN'T "making up" anything in the letter. However, no one can predict the future with 100% certainty. Whether his predictions in this letter were (in his mind) 1% likely or 99%, no one can say, but IMHO you have to take every prediction made, more so by an insider or person with a stake in the company's future, with a lot of backup research and your own logical analysis.