Actually I think most of the replies are pretty on base. They don't like giving us a road map because things change and a lot of people here on Facebook and on the steam forums have something resembling a cross between a seizure, a stroke, and explosive diarrhea over it.
Still the point is valid, with the fact that Farsight functions on very limited resources, they don't even know when certain things are going to get done first. Various features that have been talked about take varying degrees of development time and resources may be shifted to different parts of the project abruptly (we've seen it happen before) so the roadmap that you want still probably won't happen. The only thing that you could be fairly confident about is that Pinball After Dark will probably come very much later than the rest of the TPA features
TL;DR - Priorities for TPA change very frequently, roadmaps are not exactly feasible