Nah. way before that page/brin wanted to create ai (agi) long before that when google was started or in its infancy, but it seemed completely unbelievable (the kind of stuff elon musk would say)
I can't find the reference to it, but I remember them saying it in wired or similar.
For predictions? I'd say so. If I could make a statement and flip a coin to make it true 50% of the time, I could win the lottery with many 9s of precision in likelihood.
The coin-flip comparison doesn't really hold up. These weren't 16 independent questions with 50/50 odds. Some were safe bets, others were pretty far out there in 2016. Getting half right only tells you something if 50% was a reasonable baseline to begin with. Why would it be?