I could be wrong about any of this, because it's based on news reports and noth the original documents, so grain of salt, but:
As near as I can tell, the original deal said Canada would charge tolls, which will be used to reimburse the Canadian government for the funds it spent to build the span, and Michigan would get half once that happened.
So the main new bit is the language around "net profits," which doesn't seem to change this original agreement.
Assuming all the toll revenue goes toward the reimbursement of construction and operational costs, the net revenue should be zero for many years to come.