So what? Military has been doing this for decades.
So they can deliver cargo back to the starting point. Didn't say anything about ATC or the NAS integration, so presumably they had a waiver and closed the airspace for a while and obviously had adult supervision on the ground. Long, long way to go. The real trick is making it work in the system, and the system can't handle it.
Something like this might actually have utility in remote regions where they can carve out airspace without disrupting a bunch of other traffic and commerce.