Could completely uncharted islands still exist somewhere in the world, possibly with undiscovered species of flora and fauna?
It depends how big a rock you need to be to count it as an island. Unless you mean very small indeed, there are no uncharted islands: satellite based cameras can see all rocks and island -ike things more than a few feet across, and those more than a few tens of feet across will be charted – though not necessarily on easily-available maps. But there are many millions of undiscovered species of flora and fauna; tens of thousands of new species are classified every year. Islands are a particularly suitable place to search for new species, because many islends have been separated from other land masses for quite a long time and evolved their own species. Many of the species discovered every year would be regarded by many people as “boring” – an awful lot of them are new kinds of beetles. But to those studying the diversity of life, every beetle is valuable.