I'd be surprised if he wanted to 'reboot' it. When he took that break, he said part of the reason was he just isn't that interested in Chris, or in making docos- he's always been mostly into music. He also talked about how daunting it was, realizing how long the series would have to be to cover all Chris's autistic bullshit- IIRC he started aiming for a 12 part series, but soon realized it'd take much more than that, which he found pretty overwhelming (understandably imo). He also said part of why he was paused the series was that he finds it depressing (i think he said "mentally draining" or something) focussing on Chris so much (again, understandable).
So re-treading ground he's already covered, needlessly doubling up on work seems unlikely to me. I was surprised to see him going back to it at all, really. I think it'd more likely he wants to get it out of the way.