I agree it would be difficult but it’s never impossible. A campaign by some zoo 99% would not work unless they had a master marketing department but as just some random internet trend is definitely possible. But chances of that happening are entirely random if there is no influence from an outside source.
That being said there is also little chance zoos would revive the population with overseas animals even if they became popular.
It wouldn't happen. Rhinos have been popular for over a thousand years. They are one of most well known types of animals, and are common as mascots, brand ambassador/logos, and cartoons. When I did adult zoo camp a couple of months ago, we got to go in the rhino barn and people were crying at being close to them.