Since Bitcoin is a decentralized currency, there is no need for a bank because every user has access to it and can control it without any protocols and restrictions. If there were to be a bank for Bitcoin, it would mean there is no need for individuals to hodl Bitcoin personally; the bank would have to do the work. Bitcoin will remain what it is; the only thing we should be expecting from Bitcoin is more adoption and nothing more. Anything that turns Bitcoin into paper and opens it to banks would be considered a transformation to the traditional currency we have. Bitcoin is a decentralized currency and will always be, because this is what makes Bitcoin what it is.