That's an excellent question. Electric motors with high torque at low speed tend not to be efficient for continuous operation at high speeds. It's the reason many EVs have 2 different types of motors; one for getting up to speed (or rapidly decelerate), which is rarely used, and the other to offset drag on the highway. I have no idea what type of performance specs Metrolinx is expecting.
The TTC Nova eBus appears to be configured for efficiency at a continuous ~50km/h rather than getting up to speed as quickly as possible though the manufacturer doesn't really say that. Standing passengers need a fairly gentle ride so putting design effort into higher torque at low speeds is kinda wasted but this is what would be required to run up a hill quickly starting from stopped. I expect their highway coach model would be very similar if not the exact same drivetrain.
Worth noting, I'm only an enthusiast and have no relevant professional expertise.