OK, well, I will read it a few more times and see if I can extract a full understanding.
In the end, though, it may not matter what information they give us because, as BWJM quite correctly pointed out, the SNDB will provide answers. The database is the collector's trump card over what other sources would have us believe. Had nobody ever found a 2004-dated $50 note above AHJ 2230530, that would effectively be the end of the printing date and we would be none the smarter, even if the Bank of Canada later claimed they printed notes up to AHJ 2280999. Without data, there's no proof of anything. As I point out in previous online article (which is slated for publication in the March CPMS Newsletter (I think) ), there are gaps in some prefixes where no notes are recorded. Part of that is due to the information in the SNDB not being fully mature, and part of that is probably some genuine holes in numbering, and even entire reams of notes that never made it to circulation for reasons we will likely never know.