I've wondered if this tech could be useful for video games... but it's going to take more than just recording one "voice" sample and typing some text. At the very least you're going to need some formal notifications of tone, because there's a world of difference between "[sarcastic] Yeah, really." and "[emphatic] Yeah, really." and at times its a super-AI-complete problem to know exactly what the author intended without annotations. (That is, even humans would get it wrong sometimes.)

Unfortunately for the company, that video is indeed a great demo of the fact you can't just shove their technology at some text and "solve" the problem.

However, for the first time, I feel like a half-decent solution to this problem is on the horizon, rather than absurdly far away.