I would love to see Illusion experimenting on this kind of concept : it would tremendously help broaden the audience of their Studio apps.
As I stated above, my main grief with the posers are their "high effort / low reward" nature. You have to spend a big amount of time to pose your characters, select animations and states in clunky nested menus, fight with broken IK rigs and their crappy gizmos, install truckloads of often conflicting mods to fix things that should work from the get-go... simply in order to get a few screenshots at the end ? (Seriously ?)
If Illusion had to make a game where the goal is to pose characters for pictures, it would certainly push them to refine their whole approach : it would force them to make the posing process actually engaging and enjoyable for the "average player".
They would need to nail a proper implementation of the basics : an IK rig with enforced constraints, that actually uses roll joints to prevent deformations, and can be piloted from a slick UI. Once they have this feature set, a "posing idol" game could be built on top of it without too much hassle. And be actually enjoyable for players.
This is something that is truly lacking in their current system, and as long as they don't fix it, their Studio apps won't pick the interest of the mass : most of us are playing games for fun and we really can't be bothered having to fight our way through poorly-designed user-experiences (kudos to the Studio masters out there actually going through all this shit to create scenes, by the way).