Gorillas- I think it probably was too. There was a public outcry when it was announced Berlin's young male Gorilla 'Bokito' was among the trio to be sent to Shanghai- he had endeared himself to the Berlin public by escaping his enclosure and making the news more than once. So another male 'Dango' was sent instead, along with the two females, while Bokito, by then in Rotterdam awaiting shipment to Shanghai, was allowed to stay in Rotterdam where he is now the breedng male Gorilla group leader. Regarding Apes not being let outside. If correct it could be the result of one of several reasons- fear of (or proven incidence of) escapes due to flawed design, difficulty coaxing animals back inside or animals refusing to go out doors, so not let out etc. or given its high incidence here, to prevent access to harmful public feeding. Maybe the latter is most likely? While these situations also sometimes become an established habit in a zoo for no apparent good reason.