Bulk of the riders don't live along Hurontario as they are students going to Sheridan from Brampton, people who work north of Eglinton, travelling to the mall as well in general.
I have no up to date info for ridership, but when I last did data on the #19 a decade or so ago, it was seeing around 30,000 riders daily for weekday and 10-15,000 on the weekend. Regardless what day of the week back then as well today, Hurontario still the #1 route in the city and will remain #1 in the coming decades to justify an LRT in place of a BRT.
In 2003, when I wrote my first report on transit, I called for an LRT or elevated line that would see close to 100,000 daily riders by 2050, if not sooner, depending on the density that will be built along the corridor.
The only issues I have with the LRT are stop spacing, locations and the loop. There should be a few more south of Britannia. There are a few more that will be built over time for the industrial area when they are needed.
If the line does not have a bypass branch, it will be a failure from my point of view as it will keep people in the car. The current model spite has change about 2% in the last 25 years for the city at about 17%.