This seems like a no-brainer and it's incredible to me that it isn't already the case. But the CRTC has ruled that all streaming services in Canada must provide accurate closed captioning for online programmers.

The ruling surrounds every conceivable kind of show that might appear over a streaming service, including live events like sports, new shows or movies made expressly for a streamer or the rebroadcast of TV programming that a service might add to its line-up. 

I find it hard to believe they haven't already done so, but the Commission also takes into account the pressure this might put on CC outlets that do this kind of work. So it's included a timeline for when this must be implemented, although it seems a bit long of a threshold to me. 
 
"Online streaming services must provide closed captioning for 80% of their program catalogues within four years and 100% within five years. This time will help ensure that closed captioning is accurate and of high quality."

Long overdue and those who don't want to see the words on screen can simply choose not to turn them on and will never even know they're there.  

Mark the date. At last the CRTC and I agree on something!

CRTC Press Release

CRTC Regulation