I had this same thought, but my fear would be that it could be confusing/misleading. GPT-2 is really impressive but sometimes it produces phrases that look like

I had this same thought, but my fear would be that it could be confusing/misleading. GPT-2 is really impressive but sometimes it produces phrases that look like a natural language at first glance but don't make any sense when you really try to parse them, or statements that do make sense on their own but are directly contradicted by the next statement it makes. I'd hate to be learning a language and pick up nonsensical language use from an AI. My guess is that we're not quite there, and an attempt at this would end up being really confusing/misleading for the learner, but I fundamentally agree that an app could give you fluency via AI conversations and I suspect it will be done in the nearish future.