The four extant ostrich subspecies have all been described since at least the 19th C. - this is just zoos starting to catch up!
EDIT: And S. c. camelus is not at all common in Europe, so this is an interesting acquisition! That said, it doesn't appear to have been individually IUCN evaluated, so calling it 'Critically Endangered' with capitals is a little disengenuous.
Yes, the Ostrich has been evaluated as a species but its subspecies have not, so any claims to an official status for those subspecies are dubious at best.