With the current situation of IKN seen in the news, it's very unlikely that the safari park (and the city itself) will be coming anytime soon.
I both love and hate the irony in this situation. Regardless of your view, a massive portion of rainforest, home to various species and indigenous peoples, are cleared to be a part of a government project that most likely prioritized Investment from large companies and such. This proposed "Taman Safari", not only that it's very obvious that they're profit-oriented and are proposed by a big business with most likely less interest in conservation, the irony of that land taken from the wildlife and indigenous peoples to be build for a "safari park" that will most likely falsely promoted conservation and education is honestly just sad.
Taman Safari Indonesia has done very well in conservation and research (With PCBA and various other projects), it's worth remembering that they're still a massive conglomerate in Indonesia, and this is just one part of their business.