Not really. It's just meatloaf and mashed potatoes. Nothing decadent about meatloaf and mashed potatoes.
Fowl and stuffing in and of itself isn't decadent. It's the unholy Turducken combination that makes it decadent.
In this case, a meat cake qualifies as decadence. It's on a grand scale, it's a cake, and it's meat. SIX POUNDS of meat. That's decadent. That is 24 servings!
Mashed Yukon Gold potato frosting would be better, though, imho. Of course, they are expensive, but expensive/high quality ingredients make everything better. She had to use potato flakes because she had already spent $40 on the SIX POUNDS of meat that were required for the cake. What if you made a three-layer cake using different meatloaves? Like one of venison, one of elk, and one of beef (or any other game or domesticated meat)? That would be pretty cool.
I think it would be cool for a dinner party to make individual-sized cakes frosted with mashed potatoes (I would do vegetarian cakes most likely, but that's just me). However, then you're left with pretty much just Shepherd's Pie, unless you decorate them like small cakes. Of course, the grand scale of a three-layer meatcake would be lost, and that's 99% of what made this so awesome in the first place.