When did you last saw the hornbill in Itatiba? Although these are animals that have a long life, the individuals in the country might have already passed alway, once most of them came many decades ago and rarely bred. That's why I believe these individuals no longer make part of these collections, but I'm not sure. By the way, do you know when was the video of the hornbill at the passeio publico recorded? It would be interesting to watch it and know how much time have passed since then.
In my opinion, the individuals that are most likely to be still alive in the continent are the abyssinian ground ones at SP, wich I saw in my last visit in october 2020; the silvery-cheeked one(s) you mentioned at Rio and the
Buceros bicornis at Medellín that
@WhistlingKite24 mentioned.