It's just the general narrative around Tua this particular off-season. He's hired a personal QB coach. He's working on new footwork to make himself for mobile. Now he's going to be training with 3DQB.
All of these things coincide with the off-season he's expected to get a big contract extension. It's the typical "<player> is in the best shape of his life" PR speak. The quote is from "source" and might as well be directly from Tua's agent. Last off-season, it was "he's learning kung-fu to help with taking falls."