Yes, elephants are very brave. Their numbers are being reduced and yet they persevere. They have learned who the good guys are and who the bad guys hunting them down are. They can distinguish between the languages of the good guys and the bad guys. Elephants are amazingly intelligent, compassionate, and determined.
That's awesome. There's also some indication that elephants remember places with people nice to elephants. Some wild elephants have been known to go to elephant sanctuaries when injured to get help from humans. Elephant empathy is a beautiful thing. A great example is when two elephants are reunited after twenty years and are overjoyed to see each other.
I don't see the ralationship between elephants recognizing different languages and elephants being brave. They are simply animals, and perhaps they have a special talent. I don't think this language recognition is brave in and of itself. I think its amazing that elephants can do this, though, and am unsure how many other animals have the same ability.
It's an interesting fact that elephants can recognize different human languages and can then associate those languages with groups that are known threats to their species. But how does this fact relate to them being brave? Elephants are amazing creatures but this doesn't make them brave. Recognizing a threat is something all animals do and it is natural to pass on that knowledge.