While the takin, markhor and cranes have been planned from the beginning, the article you've shared does not mention any of these species at all, although they do mention getting either bongo or sable antelope (bongo sounds more likely given their threatened status). The last I heard about them getting takin was from this article from 2018:
Fota Wildlife Park plans more than bear necessities in €16m upgrade
When I next visit Fota, I will try to find a keeper to ask if they still plan to get any of those species, unless someone else on the forum can do that.
Regarding the bears, I recently emailed Fota to ask if work on the bear habitat will start this year, and they said they currently have no plans. That doesn't necessarily mean they won't come next year, so we'll just wait and see. But it will definitely be interesting, as I've been waiting years for them to come!
I don't think the space to keep these animals is too limited. I've been doing measurements of the enclosures marked for the bears and takin/markhor on Google Earth, and the designated spaces seem to be adequate at least. Based on my measurements, the area where the takin and markhor were gonna go (south from the rhinos and east from the lions) is around 5-6,000m2, and the area where the bears were gonna go (north from the rhinos and east from the tigers) is around 3-4,000m2. In addition, the area marked for cranes (as seen in an old version of the map which I've linked below) is roughly 3,400m2. I had wondered if that space could be a second bear enclosure, as it looks big enough for at least one bear, but time will tell what its purpose will be.
https://media.ringofcork.ie/wp-content/uploads/2014/07/15072220/map.jpeg