Three 12ga barrels might be OK for home defense shotgun, or for a cowboy shotgun (assuming it would be sanctioned) but I don't see it being any real advantage for hunting due to the weight and forward balance.
But, if they came out with a version that had a 12g or 20ga, a 223 to a 30-30 or 308, and a .22 LR or 17 HMR, and if it broke down easily for carrying, I could see it selling as a survival gun. Assuming the quality is decent and the barrels were properly regulated to the sights.