I must say that I am extremely dissapointed to learn that the franchise mode market will be a global one. Whilst I think that will be great in the first couple of days, I think it'll lose its novelty rather quickly once the market oversaturates, and then it'll just be a glorified sandboxmode.
The cool thing about trading animals between zoos would be that we'd have known these animals were in other zoos we'd seen before. Zoos of your friends, or, for content creators and their fans; from other content creators' series.
I'd love for there to be a possibilty to make a group of zoos working together and trading together exclusively, apart from the rest of the world. Adding to that, there is of course the problem of timelines, as others have suggested. I'd figure all zoos in franchise mode would have the exact same timeline, which is an awesome concept, but I feel like after a couple of months it'll become hard for people to just jump in, feeling like they're left behind the others with their inflated prices or at the very least being left behind in terms of how much currency they have.
But if franchise mode would have a sort of 'group mode' then people would be able to get a group of friends together, a couple months after the game has been released perhaps, and just all start at the same point right then and there.
I don't know, you've probably thought this through and there are probably very good reasons why my kind of franchise mode wouldn't work, but it just feels like a shame, as I, and multiple other people, were extremely excited by the mention of this online trading thing, only to now figure out it's not as personal and realistic as we'd thought.