To be fair, I have never heard of a city that kept a large proportion of its obsolete transit vehicles after its replacements were up and running. There just isn't the space or the money to keep these in storage.Personally I'd hope we'd keep a small but significant fleet of cars. I think the scrapping of all but two of the PCCs was extremely shortsighted on the part of the TTC and province (if I remember right, there were 15-20 being refurbished in the 90s but budget cuts led to the TTC scrapping the majority). God knows it feels like Toronto is afraid of the past and is always looking to completely eradicate any proof that there was something here before whatever our current infatuation is.
My guess is that the Halton County Museum gets a CLRV or an ALRV, the TTC keeps one for special events, another gets retrofitted into a rail grinder/work car, and a handful (maybe like 10) get sold off privately to become diners or art pieces or whatever. But apart from that, I don't think there will be any takers.
The first reason is what JayBeeGooner said: the CLRVs are maintenance nightmares, and you can get the same level of user-friendliness with a lot less hassle and some heritage cred if you get a PCC. The other benefit of a PCC is that they're not exclusive to Toronto, so they have a throwback appeal in other places. Another reason is that I think private heritage trolley lines have peaked, since quite a few cities in North America are now building modern streetcar lines, and the novelty of riding a streetcar will wear off. In fact, some heritage systems have been scrapped in cities that are now building modern streetcar systems, such as Tucson and Seattle.