I can assure you that there are occasions where you are seeing stuff very nearly on the same day it appears on the internal, that's how dedicated these guys are to making sure you are all kept up to speed on what's being done and what's yet to come.
I think part of the avoidance of giving an estimate is a need to not disappoint the fans by making a very vaporous guess and then having people expect them to hold to it and feeling let-down.
I can tell you that the team is being totally honest with you, R1 is probably the biggest project of the lot, because it needs to contain all the stuff that gets re-used by later releases, like Huds, cockpits, briefing icons etc, later releases won't need as many of those, because they'll already be present, but this is the release that contains the bulk of them.
So all I'll ask is, please, be patient, the team really is working hard for the sake of creating the best mod they possibly can, I can testify to that, so give them time, and I promise, you won't be disappointed