I just don't see the benefit for Mike to be released at this point. It's not like he is a killer whale with vast oceans he could hunt and habitate. He is an endangered species, and domesticated from birth. I would think his likelihood of dying from starvation, or being poached would be far higher. As long as his trainers show him a lot of attention and he's fed well, with that nice facility and pool he has he's probably happy as fuck.
Which is what they really should be looking for. These cats are dangerously close to extinction and I'd hope someone is doing all they can to make sure that doesn't happen.
There are havens for former lab animals, mistreated wild pets, and retired zoo animals that can't be released into the wild, but they have wide open spaces if they can handle it and interaction with their own kind, if they can handle that. Some of them can't, but they still provide a larger and more natural habitat for them away from the mad scientists and asshole tourists. There are just not enough of these facilities and all have a waiting list to get into. There is one for big cats in California . . . http://www.wildcathaven.org There is a very good one in Louisiana near Shreveport. http://www.chimphaven.org Buy some chimpanzee art and support the program.