recently the Japanese company Coincheck announced the first interest-bearing accounts in Japan in bitcoins. Despite the fact that in general the project looks quite attractive and can promote the distribution of bitcoin among the population, there are certain problems associated with the mechanisms for making profit from such deposits.
But the problem bank will not think that easy to adopt bitcoin as deposit since the fluctuation is very high.
They will not put their customer in high risk so i dont think any of bank will try to accept bitcoin as deposit. If retail market accept bitcoin, maybe it has bigger opportunity since its own by a person not government.