At Reitaisai 9, Sumikaze Midi of Project LT will be releasing a new Whiterockman Letty doujinshi. As far as I can tell (and this is a pretty loose interpretation, so bear with me), it will be a prologue to the upcoming game. There's something about a possible reprint of the original doujinshi, but I'm not entirely certain of whether this is that reprint or if it will be provided at his booth as well. Again, loose reading. I just wanted to post this.
You can check out the sample set on his pixiv here.