@animalman0341 I think there are several assumptions in your argument that lead to what I feel are problematic conclusions.
I agree that customs can hinder imports of animals, it's been discussed on other threads in the Canadian forums previously. However, if the Toronto Zoo were to taken in animals from a closing zoo (or hypothetically closing in this case), they would still run into import problems in the future. Take the Striped Hyenas for example, if TZ were to build an exhibit and take in the ones from this facility they would basically be building an exhibit for just these three animals. After they passed, what would you do with their exhibit? You mention the three are siblings so they obviously cannot breed with each other, if you wish to breed them you would need to import more and again, deal with customs. Secondly, your import options would be incredibly limited as there are only a handful of zoos in the US with striped hyenas, as the emphasis is clearly on breeding Spotted Hyenas.
Building new exhibits cost a lot of money, and while it's great to suggest that a new "permanent" Amur Leopard exhibit would bring in enough money to help fund future developments, that does not make the funds for that leopard exhibit automatically materialize. The money needs to be there to build these exhibits, good luck waiting on any level of government in the current fiscal situation to increase funding.
Of course, if these new exhibits are to be permanent, their will still have to be reliance on imports to maintain genetic diversity and work with the SSPs (intra Canadian transfers can and do help, but there is a limit on how much diversity can be maintained in three or even four facilities). The TZ cannot build a stable, genetically diverse population of animals by taking on animals from closing zoos.
Ultimately a lot of the animals the zoo takes in now are part of their focus on conservation, education and research, which more often involves working with SSPs (I realize there are notable exceptions to this, but I'm hoping they are moving away from that).