In fact, since the SEC rejected the Winkelvoss COIN ETF and the SolidX ETF, it seems less likely that banks will warm up to bitcoin. There are all kinds of reasons that banks would be hostile to bitcoin. After all, bitcoin is, down the line, an existential threat to banking, whether or not they understand it yet.
There has been talk of BTC/USD becoming less of a center of liquidity for bitcoin traders. Perhaps if the US banking system becomes too restrictive, and there are no functioning spot markets that can perform USD transactions internationally, then traders will flock to a more accomodative currency, such as the Swiss Franc (CHF) or Japanese Yen (JPY).
Traders are accustomed to using different currencies. When China came on the scene in 2013, most traders had to start getting used to CNY denominated bitcoin markets, as the biggest high-volume exchanges were located in China. Now that they're having their own regulatory issues, with Bitcoin withdrawals being frozen, the West is now dominant again in the market.
There's still Bitstamp, Gemini, GDAX, itBit where USD flows seem to be without issue. However, other exchanges, like Xapo, are reportedly having trouble with USD flows a well. So this could be the beginning of a domino effect that may harm the other major spot exchanges once large USD flows begin to appear. Currently, they are not big enough to attract that much attention, but once they are doing $100 millions, they will then get a bit more scrutiny. With Bitfinex's flows going over to the other exchanges, people will be putting this to the test with large amounts.