He shows some examples in this instagram video (link at the bottom) towards the end of these synth “rawrs” he made with Operator. I think he messed with the pitch envelope for sure, but also (possibly) automated the distortion. It sounds like the distortion increases as the attack increases in amplitude. He only uses Ableton stock plugins/effects & instruments.
Oh wait, I think he made an fm one shot and then put it in Ableton’s Sampler and did further processing in there to get the rising stretching noise. In the Pitch/Osc, I think he messed with the pitch env and the oscillator section. I haven’t figured it out but I just thought of that and it honestly shouldn’t be that hard to do (like get the similar attack time and mess with the FM parameters).