Greg, that combo can work and work well. It might have somewhat of a more 'subtle' sound to the yelp with a bit more nasal tone in the front and perhaps not a thick raspy back end, not due to Bill's building skills by any means, but more so due to the nature/characteristics of the Maple. Having said that, however, it can also surprise you depending on the density of the Butternut, which can be drastically different from one tree to the next and depending on where the call blank was harvested from the tree. Some call builders really like using a tighter grain stock often sourced from deeper in the tree, whereas, many, like me like Butternut that comes from the outer 3"-4" near the sapwood. While Maple is a hard domestic wood, it doesn't have nearly the density of the exotics often used such as, Bloodwood, Ipe, Purpleheart and so on. Their weight and density, which are not the same characteristic, will influence the sound rails differently than a hard Maple.
