But my main point was that since we already have a bunch of Bi Levels, probably more than will be needed for such longer distance services where they would be appropriate, then it would odd to go buying more of them, just for the benefit of having doors at different locations.
No, not more than needed.
In fact, GO
still has options in Bombardier order books for additional bilevel coaches (low-platform-only!), in addition to
already ordered even more bilevels that will come into service in 2016/2017, not just the new cab cars. At worst, further additional options will no longer be exercised, but they'll at least keep every single pre-existing bilevel.
There is plans to increase GO traffic by 2.5x by sometime in the 2030s. The Union station revitalization is also designed to permit a 2-3x increase in commuter traffic (the new York concourse photos really confirms that it is doable). There is also plans to push 2-3x the number of trains through Union. All-day bidirectional service on all routes, including Kitchener-Waterloo, will easily swallow up a lot of these bilevels, for example.
To do so, GO needs to buy more trainsets (not necessarily these bilevels), but they will keep every existing bilevel for a very long time. Consider that the SmartTrack GO RER route might possibly use high platforms (urban segments of Kitchener/Stoufville line), while other lines use low platforms. They could then reallocate the diesel bilevels to other lines, or the longer-haul expresses, and buy new bilevel EMUs on a going-forward basis. They can choose to buy EMUs that support both platform heights, or they might use high platforms at all stations along the route.
Less than a year ago, Metrolinx expressed an
interest in diversifying their train fleet so they will be buying something else other than the BiLevels.
Eventually, they will discontinue the BiLevels, but I don't think it will happen until around the 2040s at the absolute minimum. I feel you can bet your bank on it, Metrolinx will run the bilevels till at least year 2040 or so, even if it's only a third or quarter of their fleet by then. They are quite durable, ultramodern (for their age) and extremely well designed for their capability. They don't even look like a 1979 design, and the condition of even the older trainsets have stayed excellent. They are probably going to end up using electric locomotives to pull existing bilevels for express and long-haul trains (e.g. Kitchener) in addition to also using EMUs (for allstop trains where EMU acceleration is more important). In fact, Metrolinx explicitly said they will be
redoing the interior over the next 18 years!!! This brings you to year 2033, and the interior design lasts for more than a decade, bringing you squarely into the 2040s, and very probably early 2050s when they discontinue the last Bombardier bilevel to a museum. Not to mention, they are buying new cabs for all of them (and creating new trainsets out of the old cabs). Those will easily last several decades, and longer than a locomotive, as they aren't an engine, and the new cabs are also compatible with electric locomotives. Many trainsets almost certainly will receive one more locomotive replacement cycle (e.g. replacing MP40's with electric locomotives) even while GO buys EMUs for densified all-stop GO RER routes like SmartTrack.
GO is expanding their fleet by more than 2x, even 3x, over the next two to three decades.... so they definitely need to keep these bilevels -- every single one of them. It may be a minority of their fleet in the 2030s, but the entire fleet certainly WILL still be running for at least two more decades, and a large portion of the fleet almost definitely at least three more decades....bank your money on it.
(Fantasizing forward.... I can imagine a 60-year-old or 70-year-old BiLevel specimen still run til the 2030s or 2040s, then a coach rolled straight into a brand new museum on its 70th anniversary in 2048 or 2049 -- complete with an exhibit of enlargements of old photos of the very same coach first being publicly exhibited at the Ex in 1978.)
For this reason, we're likely going to see a very long slow evolution to high platforms on certain routes (e.g. the Kitchener route, of SmartTrack and HSR fame) that take us well beyond the middle of this century. It's also very conceivable that not all GO RER routes will be high platform, but at least one likely probably will. That said, the first GO RER trainset that Metrolinx chooses, will hugely affect the Great Platform Debate.