In literature anything "from the canon" is work that's considered historic, timeless, important or otherwise required reading. Plugins that are part of the plugin canon are considered so vital to WordPress, they're installed with nearly every site (ex: Popularity Contest, Akismet, Subscribe to Comments). Sounds like the question is asking if the important plugins should be bundled (where they can still be turned on or off) or simple coded into WP as part of the software?