Well, the guides won't include "all of the generation 5 Ken Sugimori artwork for the Pokémon", but they'll include artwork for all Isshu Pokémon from #494 to #646.
After the release of these guides, hopefully we can expect the main Japanese Pokémon sites to update with all of the Ken Sugimori artwork revealed in the guides. It's been far too long already, so November 20th will be a date to look forward to. Of course, with the way they've been going now, they may not put all of the artwork online until a later date. There has been a huge chunk of Sugimori art in recent Coro Coro magazines to update their sites with, yet they haven't done it. I guess scans are to be expected, but perfect-quality art may still be a rarity for some time.