It's also important to remember that, for infrastructure funding, times are good but that doesn't mean they will remain that way. The DRL, which is still needed, is a decade long project that probably wouldn't get shovels in the ground for 5 years.
In 5 years Trudeau and Wynne could be kicked out of office and those funds could come to a screeching halt. Hell, knowing Toronto Tory could be kicked out by another Ford and nothing will get built and all these promises will be just another map with different coloured lines on it collecting dust at the City Hall archives with all the other maps with coloured lines on them.
Again, whether you hate ST or love it, get this "I want a DRL instead" idea out of your head as it won't happen. Trudeau will NOT make an exception for Toronto and give it long term funding for a project that every other city in the country will not enjoy.
Also you have to remember that Trudeau is a politician. I think his understanding and wanting of green infrastructure is a genuine one but he still wants to reap all the political mileage he can out of all these projects nationwide. He will not tolerate the end of an environmental review and community consultations for a DRL as a back drop in Toronto in his re-election campaign. In fact it would do him immeasurable harm as the opposition uses it as an example of how Trudeau promised a lot and delivered nothing.
If Toronto wants DRL it can work on it's own plan but if they want any infrastructure for the downtown area in the next 5 years or more then ST is not the best option, it's the only option.