... so, using AI speech-to-text for stop-gap dialogue during dev has been in place since at least the early 2000s. Many alpha builds that have leaked come packed to the brim with this type of work, because it helps developers immensely in understanding flow and timings.
It sounds like this AI goes to the next level, and is used to cut costs by ensuring you can show the actor "this is what I need" and them delivering it in as few takes as possible, all the while your developers have a pretty good bit of cost-effective dialogue to use during development, keeping everything moving quickly. This means you don't need to bring in voice actors until much later in the process, instead of having them back again and again to re-record dialogue. For simple indie games, this type of AI might be used for NPCs, but for AAA games pushing performances, it wouldn't fly. At least, not yet.