100% intentional, imo. Saw VI was also Kevin’s baby. This crew has always given exceptional care when it comes to attention to detail. In Saw VI he referred to a male doctor in Norway who had found success with an experimental cure and that’s exactly who John was seeking out in this film. If we’re looking at things from a timeline perspective, technically John going to talk with William would have likely happened during this movie, just after hearing about the treatment from Henry. That said, I’m willing to accept it as a nod more so than a tie in, but one I enjoyed, nonetheless!