As for me, banks don't see blockchain as a treat anymore but a pathway to successful and instant transactions. The collaboration of the blockchain technology and the banking system is actually beneficial for both parties. I believe that if more people will be aware of crypto, more banks would still adopt it in the future
I personally don't think Blockchain is a threat to the bank but Bitcoin.
The blockchain technology is one that should be emulate to make the banking sector easier and transparent. Though, any banks who are seeing the Blockchain as a threat has something to hid and fears accountability and transparency.