The Fed Governor recently gave a speech in front of bankers. Bitcoin.com deciphered some of her quotes into normal english lol
Translation: There’s a risk our system could get disrupted by this new technology.
Translation: Our system could be made obsolete by an alternative, decentralized, peer-to-peer, open-access system.
https://news.bitcoin.com/federal-reserve-on-bitcoin/
I doubt (but do not KNOW) that the FED has any worries in the short-term re Bitcoin taking over the financial system from the banks. For sure they are going to watch developments in the Bitcoin Ecosystem.
If BTC gets to the point (years from now) where it would appear to be some kind of threat, the Central Banks then may try to kill it (with the help of their buddies at .gov), or perhaps co-opt it (regulate BTC or just buying up BTC companies).
But, the Banksters have bigger fish to fry right now: health of their banks, political problems, derivative exposure, bankruptcies...