Why not a team in Whitby… or if that’s too close to Oshawa, why not fricken Newmarket???
Generals would have to approve it first and likely wouldn't fly for a team in Whitby.
Newmarket had a small stint they played 2 seasons in the OHL in the early 90's, and since moved on to end up in Sarnia. As for Newmarket I would think that Barrie and Mississauaga would be the ones to squash the idea being on the edges of each of their fanbases.
As for Chatham being kicked around I think one if not both Sarnia and Windsor would have similar issues as Barrie and Mississauaga would with Newmarket.
Relocation is really the only option the OHL has and expansion would have to be even up 2 additional places on the map at least one in each conference to make it fly.
There's really only 3 or 4 places on the map they league hasn't tried in awhile or not at all that could realistically fly.
Cornwall, ON since they originally ended up in Sarnia would be one.
Other considerations would be (Listed Below)
Syracuse, NY
Rochester, NY
Cleveland, OH
Since those 3 places I still believe have AHL teams I would say the only place left to for the OHL is Cornwall, and I doubt the OHL would go down that path again every so many seasons we hear that places like Mississauaga have a tough go trying to sell the OHL to citizens and how fans are puzzled by Owen Sound surviving being the smallest market to not have a 4 lane highway near it.
So to close off this posting no team realistically would end up anywhere else on the map including Thunder Bay.
The OHL will likely stay the way it is for the foreseeable future.