You didn't read far enough, they'll be offering a 4 string version. It won't be a custom shop version..
The story says they're custom Seymour Duncan SuperTrons. I saw an earlier article around the time of the Summer NAMM show that had a direct front view. They look like the TV Jones SuperTron, a twin blade design. Granted, you can't tell what's underneath, could be a sidewinder design, but I can't see how anything that small could be a mudbucker.
Dangit! Back in jeopardy...nah. Between the Coug bass and my ThunderJet, I'm covered.
I do love the 50's names Gretsch gives their pickups...as Dave noted...
Middle pickup (Seymour Duncan® Super’Tron).
Neck pickup all-new Rumble’Tron.
Ya gotta love those names. They'd fit right in with Oldsmobile's Hydra-Matic transmission, Chevy's Powerglide, Buick's Air Poise suspension, Lincoln's Invincible 8 engine, and Chrysler's Hydraguide power steering and Firepower V-8.