I would highly doubt any bank logo will be seen while BMO has the naming rights to BMO Field. The only exception to this is that you will see Scotiabank stuff during the Gold Cup games as they are title sponsor for CONCACAF Champions League and the Gold Cup.
(full disclosure, I work for Scotiabank, and in the same dept as the sponsorship people, but I have no inside knowledge. I didn't even know about the CONCACAF thing until the press conference!).
That being said, I am happy I don't have to have a competitor's logo on a jersey this year, if I choose to buy a new one!