You are probably right, but I don't know as much about the history of the Toronto Zoo as ZooBeat members Zoogoer2000 and Quartz92. Those two are the people to ask...
I'm not sure what the future holds for dhole in Toronto. Our two females are eleven years old (atleast) and I don't know if there are any plans to source new animals in. I don't think this exhibit will be on it's way out for quite some time, though. It does make a nice habitat for this species.