The business with not using an existing IP for other models such as free-to-play seems pretty key to how Nintendo thinks.
It seems they tend to create IP not just for the sake of having random characters nobody's seen before, but to support a concept or idea. I.e. people complain often that Nintendo doesn't make enough new IP. But typically in the industry, new IP is created merely to graft onto an existing game framework and sell it as something "fresh" - like all the copycat first person shooters that chase the COD dollar. Nintendo didn't get any respect from the enthusiast crowd this gen for all the new IP they created like Wiiverse stuff (there has to be a name for Miis, Wuhu Island, etc), but it was kinda major new IP. Created for new kinds of games and new purposes.
When they came up with a fresh and original combination of gameplay ideas for Dillon's Rolling Western on 3DS, they did indeed create a new universe and cast of characters to support that.
If they become concerned and interested in striking out into various new territories once more, it seems we'll see a variety of new IP.