I don't see it making much of a dent in terms of dealers who already have a client base. However, they will lose the very, very part-time smokers who will go halfsies with a regular smoker friend. It's just easier to handle the transaction yourself. Toronto (or virtually everywhere in Canada) doesn't have visible street dealing of weed, so a tourist or business visitor is unlikely to encounter dealers. When retail stores open in April, you won't find a single person unfamiliar with the province asking where to find weed.

Someone who most assuredly wasn't me ordered a bunch of stuff online to see what the experience was like, and upon hearing of rollout delays, hit up the other guy to supplement in the meantime.