The Territory Wildlife Park obtained permission and permits to collect Oenpellis years ago, but still "haven't got around to it". I spoke to a couple of their staff and was told that it was too difficult to find them and that they were trying, but several years later that excuse has worn extremely thin and it seems clear that for one reason or another, or several, they actually don't want to breed them. I know two non herp people who have found them by accident while running around Kakadu as non herp inclined tourists with cameras. It is quite funny to have someone who knows nothing about reptiles say "I saw a snake and took a picture, would you like to see it?" and then see a photograph of an Oenpelli!
Releasing captive bred babies into the wild will cause much, much more harm than good. Generally speaking, the only time it is a good idea to release babies into the wild is when the population has declined for some reason and that factor has permanently been removed (or, very rarely, when you want to start up a new population). This is certainly not the case with Oenpelli Pythons and it isn't right for us to be releasing animals to the detriment of a population and ecosystem just so that misguided people can feel good about themselves.