So it will be a net gain for US at the cost of Canada
The Canadians are so subservient to the US that any American president could phone Canada up and ask for literally anything and the Canadians would give it to him immediately at any time no questions asked. The president could ask to sleep with the prime minister's wife and the prime minister's wife will be flown in the very next hour.
Canada being a vassal of the US already, any secession or accession would be purely performative and would only change the de jure state of things rather than what materially matters.