Yes that's been the news all along. It's not 100% unique to the raptor, it's still a 3.5 ecoboost, and they're sharing pretty much all of the technology/parts across the board as the 2017+ regular f150's are also getting the new engine, new dual injection, etc. The GT supercar is getting the new 3.5 with even more upgraded parts. The Raptor is just a variant of that all-new 3.5 that every f150 is getting with some tweaks. Ford has done this countless times over the years. 03-04 cobra's were still a 4v 4.6 just blown with different internals. 99-04 Lightnings were still a 2v 5.4 like all the other f150's just blown with a forged crank and lower compression pistons. Prices weren't sky high compared to the regular versions of those motors. Small premium but not ridiculous. The Raptor getting a variant of the new 3.5 makes sense, a different set of pistons, maybe a cam profile change, and turbo/manifolds, small peanuts in the grand scheme of things but enough to make it a powerful raptor specific one.
