I read a long time ago about a masterplan at this zoo that talked about building a new arctic complex with exhibits for polar bears and pinnipeds. I also read that the free space left by the bears would be occupied by rare Chinese animals, such as giant pandas and even golden monkeys.
There was a "backup" plan in case pandas wouldn´t come in, some another asian bear species (so probably sloth bears?)
But any construction here probably wont start before polar bears move in their new exhibit (and construction of its should start by the end of this year, at best)
About golden monkeys - they are as "problematic" as pandas? If so, its a shame.
About those plains inhabitants and kiangs - only species so far mentioned are wisents, who will leave the areal of zoo but stay in Prague (big, natural paddock should be build for them in different part of city)
About rest, I may just guess - bisons could probably leave zoo? They are even bred as "farm animals", if I am not mistaken (even here, in czech republic?), so probably no need to keep them in zoos, where they "just take space" for another species...
Peccaries could move in lower part of zoo, nearby old pachyderm house which should be refurbished into South American house (not sure however if, when and how will be this project realised)
If somebody have any real info, I´ll be glad for corrections