IDK exactly what Duolingo is, but it sounds like this new product gives you practice with spoken conversations? I'm unexcited by the idea of doing that with a computer but still, spoken language learning is completely different from written language.
The best thing for spoken language acquisition from my perspective has simply been listening a lot to live human speakers of the language, in person. That means either take a class with a human instructor, or travel to wherever they use that language. It's ok to start with very limited ability. Bring a dictionary things will sink in over time.