The difference between building up a large breeding colony of Little blue penguin though is that in a worst case scenario, it wouldn't be difficult to rebuild. These birds routinely arrive from the wild, injured and unreleasable.
By comparison, the loss of the entire flamingo flock would be far more devastating and problematic (of not impossible) to replace. Like
@Zorro has said, surely the zoo would have looked into it if they felt it was a viable option to import more.
It's unclear if they will (or can) import again, but for the benefit of the flock, I hope the flamgino aviary happens sooner rather than later. I have no doubt breeding success would increase exponentially.