It's already happening in Canada. IPTV is highly regulated and prices are high. At look at most of the services reveals large packages, missing channels, limited features and lack of good PVR options. They typically try to mimic offerings from incumbent BDUs but do a bad job of it while offering very little in savings. Compared to offerings from Rogers, Telus, Cogeco or Bell the value is not there. From what I've gathered, they typically have only a few thousand subscribers, not the hundreds of thousands they need to be profitable. It's not that they are shrinking like Sling TV or DirecTV Now, they never grew to any size in the first place.
Another factor is the difference in business practices in Canada. There is no Canadian equivalent to Sling and the equivalent of Direct TV is owned by the cable industry. Telecoms and cable operators do not try to compete in each other's territory. Bell and Telus dominate telecom services in most of the country and they have their own IPTV offerings. They both offer satellite TV so there is no real competition there either. The situation is much the same on the cable side. Shaw, Rogers and Cogeco dominate and don't compete directly. Each has or is launching it's own IPTV service and Shaw owns the only other satellite TV service. These same companies also own the bulk of the Canadian broadcasting and internet industry.
That leaves a few internet startups (TPIAs) to try and compete in IPTV. They don't have the capital or resources to do so effectively. What makes it worse is that they must buy almost their programming from Bell, Shaw, Rogers and Cogeco and sell it over internet infrastructure owned by the same companies. That allows the incumbents to inflate costs and squeeze profit margins to almost zero. Due to regulation, US and overseas companies cannot compete directly in Canada so that option is not available.