Actually no, they are contracting out a new supply of Diesel trains to be manufactured in Quebec.
This is completely incorrect.
The only train order that GO has inked at the moment is one for 20 more MP40s that are currently being built by MotivePower in Boise, Idaho. These are scheduled to arrive starting in May of next year, and will take the total fleet size up to the largest it's ever been by a considerable margin, although the plan is to keep gradually decommissioning the old F59s. In any event, because most service improvements in the next 5 years will be during off-peak hours, engines that today are being used only for rush-hour runs will simply get used more. As such, this order will meet medium-term needs quite happily.
At the time this last order was announced, GO made noises about working with MotivePower to get the wheels turning on designing a new dual-power locomotive option for a possible order some years from now. This was a purely GO-staff-driven move at the time, as GO was still separate from Metrolinx and the RTP had yet to be finished, meaning they were working purely off the MoveOntario 2020 directive that Lakeshore E. & W. were to be electrified but nothing else.
Since then, the RTP has indicated that electrification is on the table for much more of the GO network than just the Lakeshore, and the Metrolinx electrification study has begun. In its Terms of Reference it's been stated that EMU options--both FRA-compliant ones that might be comparatively pricey, and non-FRA-compliant ones that wouldn't be--are going to be actively considered.
Until that study's finished, you can be damn sure Metrolinx/GO will not be ordering any more locomotives. Not only would it be nuts, it would be entirely unnecessary, as there's no looming locomotive crunch.
What you're probably thinking of with this Quebec reference are SNC Lavalin's existing stock of older DMU railcars that they proposed using on the Pearson link. It's possible those will get refit in Quebec.