This does not pertain to polymer notes, but it may be of interest that the Bank of Canada did actually confirm an insert replacement note, when collectors were first discovering them.
See CPMS Newsletter, Dec. 2005, page 100.
I have seen that letter from Dec. 2005 and I believe it has formed the basis for many of the insert replacements. Independent observations of bundles did show evidence of insert replacement of sheets for journey series notes, particularly the sheet inserts.
But ever since the single note inspection process was introduced, (and the Bank of Canada has publicly indicated this was done with the $5 and $10 Frontiers Series/Polymer Notes and all notes printed since 2013), there was no need to replace notes that were found to be unsuitable for circulation at the time of packaging. Even the earliest bundles of the $5 and $10 Frontiers Series Notes had missing notes from a sequence similar to what we find in bundles today.
The Bank of Canada has not confirmed publicly or otherwise the replacement ranges of either the Polymer Series Notes or the Journey Series Notes.
The GPMC says that "replacement notes have been identified by researchers" Unless I am wrong the GPMC has never been able to get any specific information about all the replacement note ranges that are shown in the catalog, from the Bank of Canada.