Sounds intriguing and would seem to be a bigger draw for the fans than an intra-squad scrimmage, but I'm not sure it would serve much of a purpose for the team or coaches. Teams don't want to get anyone hurt and wouldn't show what they can really do. I think it might be the equivalent of an NFL week 4 preseason game and those are pretty disinteresting. Probably wouldn't be any more telling than the typical spring game. On the plus side, it could be used to generate more revenue.
I also think this is what Landlord was probably referring to, but I'm not sure because he didn't respond so I don't really want to speak for him. But...what's the point of holding the scrimmage if everyone is half-assing it? It kind of goes back to the threads about conditioning and the level of intensity of practice. Injuries are going to happen. It's just the name of the game with football. But if it's an 'understanding' that your practice or scrimmage isn't full-speed, then what's the point of even doing it?
edit: Landlord responded when I was typing this...I predicted the 'injury' argument...but not the 'scouting' aspect. I'm not sure...I think even in a scrimmage, both teams would work hard to win, but still not show their entire hand.