Sounds about right. Milton would be a pretty dear penny, it needs to be big enough of a purchase for CP to build a bypass track somewhere else (e.g. 407 corridor) and simultaneously still legally satisfy shareholders despite the risk of terminating the CP mainline service. And it's definitely somewhere in that territory, given how densely populated the Milton corridor is. Metrolinx got lucky with Lakeshore corridor ownership.
And you know, you might already own CP stock, or your monthly pension cheque may in part come from CP profits! As part of your bank's favourite mutual fund, your company's pension fund, your family's university education fund, your teacher's pension fund, even our dear Canadian CPP* pension fund invests in stocks too! So YOU might already be an owner of CP rail already, without knowing it!
*
It's true. Our CPP owns shares in both CN and CP.
list of investments CPP owns. So if you're old enough to be collecting your pension today, some of your grocery money is coming thanks to your own hidden CN/CP ownership! (A tiny percentage, but it's there).
But you never know. Metrolinx might actually pay a pretty penny for more rail eventually -- maybe not Milton but an easier step of purchasing a slice of rail corridor all the way through to Hamilton's Grimsby sub (within 10-20 years). This major track purchase would probably be cheaper since only a few freight trains run through West Harbour per day, and CN would still keep running rights and/or parallel CN-dedicated trackage. This is long-term concept but several steps have already done towards this, with the earlier proposed Lewis yard & Confederation GO now becoming funded realities, so this is a good crystal ball of Lewis Yard's future and a potential portent of eventual Metrolinx purchase of Grimsby sub (beyond current 10 year plan).
Ultimately, this is certainly beyond the Wynne-announced 10 year plan, but Metrolinx does have a strong desire to electricify RER all the way through Hamilton via the CN sub (West Harbour, Confederation) to their Lewis Yard layover (
Page 119 of Metrolinx Electrification Project, Part 2, Conceptual Design Report, found in just one PDF as part of massive collection of electrification-related PDFs found at
www.gotransit.com/electrification) Page 63 to 94 is a fun read about electricifation planning between Burlington through to the Grimsby sub all the way to Lewis -- so many pages of relatively recent due diligence already about electricifation all the way to Hamilton already. They have electrification of GO to Hamilton in three phases called LW1 (to Oakville), LW2 (to Burlington/Aldershot), and LW3 (to Lewis Yard Layover past Stoney Creek), and what Wynne/Steven publicly announced was electrification of LW1 and LW2, so LW3 electrification is bumped to a future phase beyond 10 years, but it was apparently also a raison d'etre of Lewis; since that trainyard is ultimately intended for electrification someday. Digging these PDFs give you a nice crystal ball of what Metrolinx wants to do eventually, even if it's beyond government announcements (e.g. the current 10-year RER plan, which would probably end up taking 15 years including delays), and gives you a rough idea of what sections of rail that Metrolinx is shopping to buy eventually "at the right price". The plans are more solid than lots of past ones like GO ALRT, given how several parts of the plans are actually ending up happening in the last 10 years, and what is now being funded today well after these reports were published in 2014, are largely in line with the plans. So let's hope the momentum continues. Ultimately, once the CN rail degrades sufficiently (e.g. maintenace becomes more expensive than simply selling out to Metrolinx), CN may sell part of the Grimsby sub, get Metrolinx to renovate and upgrade it, and benefit from running rights paying less for maintenance -- given CN don't run the Grimsby sub nearly as often as CP runs trains on Milton. So, reading the tea leaves, we will probably hear an announcement of a purchase of Grimsby sub (even if not including part of the Hamilton Junction) well before we hear an announcement of a purchase of the Milton line. And even it might not ever happen, you can be pretty sure that it's very far more likely than Milton.
I know, doesn't answer the Milton conundrum. Milton trains are the among the most overcrowded GO trains, and apparently also in most of the Western world (you have to see places like India and China to see trains more crowded than Milton peak GO trains). Heaving nearly a SkyDome's worth of people sardined on just a mere 9 GO trains daily. While lucky Lakeshore GO users have seen the peak trains become a small smidgen less crowded over the years with fewer standees and more people spreading to now-relatively-frequent subsequent trains coming in a few minutes later that always has seats except during sports events. Milton-related PDFs are quite absent from a lot of recent Metrolinx planning documents. Thousand and thousand of pages of PDFs abound, most boring reading, but plenty of nice railfan-worthy info. Sorry to be the bearer of no good Milton news in my PDF sleuthing.