I was the author of the Canon CAPT page.
While the CAPT installation procedure is indeed non-standard, this is the only way I have managed to successfully install a Canon LBP2900 via USB, and a Canon LBP6310dn via ethernet on both Arch Linux and Linux Mint on three separate computers. This prompted me to document the steps in the Wiki, after adapting them to Arch Linux from the original, linked, Ubuntu article.
Furthermore, adding a printer to CUPS using lpadmin is a perfectly valid method.
Did the person who questions the instructions even attempt to install a CAPT printer himself, before disputing the factual accuracy?
Canon's own installation instructions use this method, rather than a standard installation procedure using the CUPS web interface, although they don't work due to the port number being incorrect.
While CAPT printers are detected by, and can be added via the CUPS GUI, they do not work.
Removing the Accuracy Dispute notification.
I think the title for this page isn't appropriate as it doesn't discuss any printer specific problems as such, but rather the installation instructions for specific printers.
In fact, I'm not convinced it is a good idea to have all these printers on a single wiki page. It makes the article unnecessarily long. It would make more sense to use this page as an index page, providing links to each specific printer's own wiki page (similar to the Autostarting). This avoids the page becoming excessively long and complicated, whilst at the same time making it easier for users to find instructions for their specific printer.