Well, of course some people do want to call it language, but so far it's not clear that it is. We might say it's so complex it's more like a symphony than birdsong, but a symphony doesn't necessarily have anything like semantic content. Given the way whale songs evolve over time, with wanna-be whales imitating the cool whales, it's quite possible that it's pretty much all showing off their talents rather than communicating ideas.