Stop dreaming about AI in Melbourne and Taronga, AI is not working well with gorillas. As far as I am aware of, the only infant ever produced by AI is Rigo`s son Ya Kwanza. And as Pertinax pointed out, Rigo`s sperm quality will be pretty bad now given his age.
Melbourne will most likely bring in a new male to breed with their females within the next years. So no need to ship the young females away. Temporarily sending Johari to Taronga wouldn`t work anyway, since she couldn`t return with an infant without it getting killed by the future silverback. And gorillas are animals with very complex social needs, you can`t just ship them around for breeding like horses. Introducing a female to an existing family and then removing her a year or two later will only disrupt the social bonds and disturb her.