Those banks will end up losing customers, these crypto bans will definitely be temporary, they have to accept the fact that crypto will be everywhere in the next 5 years, although, I don't see cryptocurrency to dominate fiat nor make people rely more onto crypto, fiat will still be dominant but cryptocurrency will be beneficial to everyone, banks will have to remove these bans and integrate cryptocurrency and give the customers what they want.
The number of customers will not be lost by such bans because of the fact that when it comes to buying and selling crypto, not a single bit of confidential information is revealed, almost just a regular money transfer method, the bank can investigate the origin of such transactions but such action is not their idea, except in cases of too obvious disclosure of crypto, otherwise the bank will still handle it as usual. The ban is just stating their position on the side of the country and the government but they are not stupid to drop the source of profits from crypto, too many potential and wealthy customers here.