Hi Amethyste,
I don't think anyone here knows for sure yet what's inside, but I can assure you that pitch preview is number one on my priority list too, and I'll be digging around inside as soon as I get it. For now we know that the tuner output is a fixed (not volume-modulated) output and there is a good chance that the front headphone jack and its volume control could be routed to the fixed signal. I think that the exclusion of any pitch preview on a presumably pro-level instrument was really ill-advised, and perhaps shows that they had a relatively small group (if a group at all) of players with which to consult.
For the short term the tuner output can be routed through an external mixer for PP, and that would even give some opportunity for some filtering on what will probably be a buzzy square wave output. But stay tuned, pitch preview is a first priority for me too, and I'll be looking into it right away.