I'm not sure if this is a realistic figure, but it seems to be one of the most bullish calls in some time.
I personally don't like these kinds of predictions for two reasons.
One is that they rely on the premise of bitcoin "succeeding", but yet, what is the criteria for bitcoin to succeed? If it's solely to fulfill its monetary function, hasn't bitcoin already succeeded, or at least partly so? Or is success measured by adoption, or prices?
Secondly, these speculative predictions are usually baseless. It doesn't matter whether or not the person speaking is a Paypal executive or not, I personally think that the 250x growth figure is simply an arbitrary number that he had thought up.
I don't think that this kind of growth is impossible in the future, if we do have mass adoption of BTC and inflation of fiat, essentially increasing the nominal value of BTC even if adoption doesn't increase. But it's definitely unlikely.