If you read the article carefully, it looks as if this was 'leaked' rather than announced publicly in the first place. I can't see any benefit in them making this public voluntarily.
Good point, it seemed that the zoo were being open about it from the fact there are quotes from people within the zoo. However, it could be that it was leaked and the bosses are now being honest, because there is no other way to go.
The last time I checked, there was no announcement on the website or facebook from the zoo itself.