I would love to see where you come with those number from.
It is a lot likelier than you believe, I'll bet you.
Nothing scientific about my prediction as I am not a transportation analyst. I would like to say there is a 0% chance in the next 15 years, but it is really difficult to predict beyond 5 years down the road if some transformative technology comes about which makes cost of constructing and operating high speed rail into a completely different economic environment. I think it would be very cool if we could get high speed rail / hyperloop built here, however I don't believe the economics support it.
First of all, there is no high speed rail in all of North America, unless you choose to count the limited network in the eastern US around Boston-Washington. With no precedent in nearby regions, this increases the risk of companies going forward with such a project, especially with such a relatively low population base in Calgary-Red Deer-Edmonton. If the economics aren't there to build high speed rail in places like California (or Ontario if you want a Canadian comparison), even with heavy government subsidies, the economics are surely not here in Alberta. There is a large need for government subsidies for high speed rail to happen, and there seems to be a serious lack of enthusiasm for funding this other than lip service. Traffic is not as much an issue in Alberta, and commutes between Edmonton and Calgary are not prohibitive.
While high speed rail is a time saver, it isn't as much as one would hope for. If travelling by vehicle, driving from a home in Edmonton to a destination in Calgary is about 3 hours. A direct high speed rail between Edmonton and Calgary is likely going to take an hour, which would be 2 hours of time saved. However the time to get to a high speed rail station has to be accounted for, then the time needed to arrive early, get through security, etc. Assuming a central location means those downtown could probably access the station within 10 minutes. However those from other sectors of the city would probably need up to at least 20 minutes to access the station by vehicle, and upwards to 40 minutes if accessing by public transit (if not situated adjacent to an LRT station connected to the network). Those in the south side of Edmonton, or living near the Henday, would already have low travel times to Calgary relative to others in the city, and time savings from residents in those quadrants of the city would be less incentivized to take high speed rail.
Cost would also affect ridership. One has to pay for transportation to the high speed rail station (unless have an ETS pass or live within walking distance), including parking, taxi/Uber. Cost of the ticket, as well as cost of transportation in the destination city (rental car, public transit, Uber/taxi). In the case of rental cars, this is another time disadvantage (same could be said for public transit as well if reason for going to destination in destination city is outside the downtown core). High speed rail also doesn't allow the same cargo capacity or flexibility of having a personal vehicle (although same could be said for taking bus/airplane as is done currently).
From the perspective of most potential riders doesn't provide enough of time savings, or cost savings. For a significant amount of people, there would be a giant advantage to high speed rail, however this population is simply not large enough to support the economics for the project. For business travellers or other personal trips that currently use airplanes would be the primary beneficiaries, so largely it has to be viewed as how much do these customers benefit from high speed rail over airplanes. All of this happening in a time where head offices are diminishing in Calgary, and ease of remote meetings since Covid really puts pressure on the benefits of high speed rail.
I think it would be really great if high speed rail could work in Alberta. However it is of my personal opinion that the costs of constructing and operating are simply too high, ridership would not be significant enough, and would have to rely on heavy government subsidies with giant losses to be part of the business model (which could be fine if you have the belief that subsidizing such a project has a net benefit to society).
In the next 15 years, I believe this is impossible. In the next 50 years, who knows, I'd say maybe...