Being technically so similar to VIA Rail's new fleet of Siemens Chargers + Venture carriages, I wonder if at some point in the future operations will be tendered out or in some way shared with VIA?
Apart from maintenance, I think it's a mostly provincial led operation. Ontario Northland Railway is owned by a Crown agency called the Ontario Northland Transportation Committee, who also own the regional coach company and used to operate an airline (plus weirdly a telephone company, which they sold off just over a decade ago).
So it seems to be a kind of one stop shop for transport and formerly utilities in the region, aimed at development of a regional transport network.
Given the same company also operates freight services and owns the infrastructure, it probably makes more sense to provide the service all in-house (as opposed to the normal North American model of leasing rights on private tracks owned by a major freight-based operator and public operations, which are sometimes subcontracted out).