I will not say replacement, but a way to improve their technologies yes. Moreover, this is why different banks are already working on the subject and that some have already been talked about on the proposal of the blockchain solution with banks
Banks have been working for a long time to use blockchain in their work. But not all banks are working on creating their own product. It's easier to use a ready-made solution by working with Ripple. Therefore, we see that banks respond to changes by adapting to new realities.