Those are Western Tufted Deer, not Japanese Serow. That would make even less sense. I liked the design better when it had binturongs, milky storks, and hornbills.
I think the original plan was to do the exhibit on the hillside where the Protea garden was, along where the WGASA bushline is before it went above the old Tiger and Lion exhibit. I have the old renderings in jpgs on my computer, except one where they had a rendering of the view to the Asian field exhibits.