It doesn't seem like he's invested in any crypto directly. He has investments in some fintech, but as far as I can tell those aren't in any companies where crypto is the main component of their business plan. It's also important to distinguish between his opinions on the potential of distribute ledger technology vs. crypto currencies themselves. You can have the first without the second.

There are also levels of conservatism: Buffet still takes risks. In any given year, there's a possibility that he loses money, even if he's amazing in the long term. This is very far from the extreme end of conservative investing where, for example, someone 2-3 years away from retirement shifts all of their investments into a low-yield guaranteed return investment to ensure that a temporary downturn in the economy doesn't wreck their ability to retire.