Servicing of the engine would indeed be made in Canada: https://www.saab.com/markets/canada/press/saab-chooses-standardaero-to-maintain-gripen-engines-in-canada

You still need to purchase the engine and spare parts from GE.

I suppose Rolls Royce and Volvo could propose alternative engines, but I assume that's as much dev, tests, certifications, so additional cost.