Very surprising that we're seeing printer letter I now, despite that many retailers refuse to accept cash during these difficult times. I guess it's safe to say that denominational letter G will be recycled on the $10 bill, once the FF* series runs its course.
One user (whose name is not mentioned), many years ago, did claim that denominational letter G would be on tbe ten. It turns out he will have been right, most likely, and this could imply he may have inside information or connections with the Bank of Canada.
The introduction of printer letter I on the five will be the first new printer letter for the five in nearly two decades. If not for printer letter A prefixes sporadically released from 2002 to 2009, we probably would have seen the printer letter I ages ago.