I expect sound guys are becoming spoiled with the proliferation of gear like Axe FX 2, Kemper, 11 Rack, etc.
What you're talking about sounds like he's encountered a Two Notes Torpedo Live or Torpedo Cab. My torpedo live allows sound guys to D/I my guitar and I can run through it into a cab for monitoring, or I can use a monitor on the stage.
The only amps that have a 'DI' out are the new Mesa ones with those terrible, build in cab clones. Technology is advancing and as a result, audio techs can have their proverbial cake and eat it too. This strikes me as being a bit dangerous...