Not really my area - I tend to stick to poltergeist cases and SHC - but I did come across a paper a few years back that looked at how geographical features like large bodies of water might concentrate or amplify anomalous reports in a region. The Great Lakes basin is a genuinely unusual environment in terms of atmospheric and electromagnetic conditions, and theres a reasonable argument that whatever underlies cryptid sightings (whether thats a real biological entity, a perception phenomenon, or something else entirely) could cluster around such areas.
What I'd want to know before drawing any conclusions is whether the reported increase is actual new sightings or whether its more people posting old accounts online and giving the impression of a spike. That conflation happens constantly in paranormal research and it skews everything. Has anyone done any kind of timeline mapping of the reports? Dates, locations, whether witnesses had any prior knowledge of the Dogman phenomenon before their sighting? That sort of baseline data would help enormously before we start theorising about causes.