The current Aprilia Pegaso (both the trail and the "SM" version) are built around a Yamaha engine. That new BMW seems to be sporting a revised version of the engine found in the F650GS. No similarities here.
The new BMW has USD forks on every version, where the Apriller has conventional ones. The Aprilia has the chain on the left side, where the BMW has it on the right side. I do not see many similarities between these two bikes, and I'm pretty sure that apart from things like controls, the wheels on the SM version, and the brakes, there aren't that much common parts. Not the frame, and not the engines.
The die hard version will not be a stripped down Aprilia Pegaso trail, but more some sort of a well built LC4 competitor imho.
I might even want one!