On the subject of Toronto-Kitchener-London, Metrolinx recently released a
preliminary design business case for what to do at Silver Junction - the interlocking where CN's Halton sub (CN's main line) intersects with the Metrolinx-owned Kitchener line in Georgetown.
The CN-owned mainline portion between Silver Jct and Bramalea, and Silver Jct, in particular, is the main bottleneck preventing decent service to Kitchener and beyond.
As you can see from the ES on pages 1-3, the "middle" option of having an enhanced surface crossing at Silver Junction allows for GO to run 2 way all day service (I think at hourly frequencies to Kitchener) with a travel time of 98 minutes. It's in line with the existing budget, but it doesn't leave any space for improvements of any kind, and would require precise train meets.
For an additional $200 million, they could build a flyover (option 3), that would allow for more frequent, faster service. Metrolinx seems to suggest that it may not be worth it because it only allows for marginal travel time improvements (90 minutes to Kitchener instead of 98), and because they may not be anticipating anything beyond an hourly service, let alone service past Kitchener. But I think it's pretty clear that this grade separation unlocks things like TKL HFR, or even space for HSR in the future, as well as much more frequent service to Kitchener than just an hourly milk run.
Securing that extra $200 million to ensure the grade separation is built seems like it would be a prudent investment. I think VIA is AWOL on anything in Southwestern Ontario, but it would be a good project to lobby the Feds for.