Investment Banking has been considered an area in finance that is less vulnerable to automation, compared to others such as Trading. This no longer seems to be the case as Google is seeking to use API's to automate vast amounts of work that are traditionally done by Investment Bankers.
My thoughts: Banking is a practice that will always be built on relationships, especially at the higher level. Automation will probably never replace this even at very advanced stages. However, that isn't all that a banker does. And if the routine grunt work that analysts usually have to do can be done by AI, there will simply be less demand for Investment Bankers as a larger percentage of the overall work done by a banker is instead done by AI.
I think it will be a relatively short period of time (or at least sooner than we think) that the work of two analyst level bankers can now be done by one with the help of automation, and as they get smarter and smarter, maybe 4 or 5 to one. Seniors can then be focused on the networking, relationships, etc.