Eh, I don't think that means anything really.  He understands what bitcoin is basically all about and has chosen not to invest in it--plus with all the money he has, he'd have a very hard time buying any without coming close to cornering the market and in the process driving up the price.  He's got enough investments in stocks and businesses that are making him tons of money, so he doesn't need to buy any bitcoin.

I don't know about $250k by 2023, but it certainly could happen.  I never thought bitcoin would hit $10k when it did the first time, so I've kind of learned to expect the unexpected.  2023 is a ways away, so it'll be interesting to see how it turns out.