The same logic could be applied to most of the Corridor inside Ontario. Toronto-London is 6 lane minimum the whole way and still getting jammed up. We're at 6 lane minimum till Coburg and probably going to 6 lane till Belleville, if not Kingston by the end of the decade. So there's absolutely a strong argument for the province to start incorporating rail development.
Going from Coburg to the Quebec border was estimated at $2.5-3 billion in 2018.
If VIA is going to take another decade just building Toronto-Ottawa-Montreal, and a decade after that getting to Windsor, there are real costs to the province. Queen's Park should be asking if they can do it better.
Question (since I have never been on the 401 west of the 403): is the 401 jammed up all the way to London? GO has already extended its service to KW, and, if it can be justified, extending it to London (about 80 km beyond Kitchener) could be a future logical step. Do you beleive that traffic congestion will extend beyond London anytime soon to justify GO service beyond London to Sarnia and Windsor?
East of Toronto, GO is planning on expanding the Lakeshore East line to Bowmanville (about 16km east of Oshawa), but while this has been planned for several years, AFAIK, there is no date for it to be completed. Also, while it is possible that they might want to widen the 401 to 6 lanes to Belleville (about 125 km east of Oshawa) or Kingston (about 125 km east of Oshawa) by the end of the the decade, the question is what percentage of the passenger vehicle traffic (i.e. not trucks) on the 401 is going to/from Ottawa, or Montreal (the major destinations served by HFR)? As a result, how long would they delay the need to widen the 401 east of Coburg by accelerating HFR?
Regarding that article, I can't help but wonder if a large percentage of the problems with the 401 east of Coburg is related to truck traffic. I suspect that finding a way to get most of those trucks off of the highway and on to rail would do far more to improve safety than widening the 401 to 6 lanes. Granted that is easier said than done.
I am not trying to argue against HFR (it certainly has value), it just wouldn't provide the same savings in road infrastructure that improved GO service provides to Metrolinx. I do see Metrolinx eventually taking over responsibility over regional rail to communities beyond the GTHA like London, Coburg, Bellville, and maybe eventually even Kingston, but struggle to see them seeing significant financial benefit in taking over intercity rail to more distant destinations like Ottawa and Windsor. IMHO, they would rather leave that to VIA Rail, even if the federal government is being slow.