As Chris says, it's not a priority right now - I am but a single dev, and I need to make sure that my focus is on getting content out for everyone :)
That being said, yes, there will be new Hidden Voice lines, as well as the ability to read the minds of many, many more people. But in all likelihood that will either be plugged in piecemeal over the course of the rest of development, or put aside until the game enters beta.