My first explanation was specifically to the question of whether or not a current member was actually eligible. The answer is yes, because the word “former” is really signaling the fact that you are not holding two jobs. At the time of appointment, you would have been “former”.
It did not in any way shape or form limit or put in place some kind of a temporal restriction on when “former” actually occurred. If you ceased to be a judge five years ago, you would still be eligible under proposed paragraph 81(2)(a). If you were a member of a federal or provincial board, commission, or tribunal a decade ago, you would still have the qualification of being a former member of a board, commission, or tribunal.
Whether or not someone who has been out of a position for a given length of time is of interest to the Governor in Council when looking at the whole appointment process, I can't speak to that. It depends on the particular individual and the particular characteristics that are in play at the time.