I see the gestation of Gene's Vision 2.0 a little differently. I don't think it stems from the development of TNG as much as it's a byproduct of Paramount firing him after Star Trek: The Motion Picture and handing Harve Bennett the franchise, because it was a way to differentiate "his" Star Trek from what Bennett was doing and gave him a rhetorical cudgel he could use against Bennett privately in memos and publicly at conventions in the 1980s. Then in 1987 he was back in a position where he could make good on the "vision" that formed in his mind over the preceding six years, he married it to David Gerrold's ideas for a new Star Trek series, and, BOOM!, Star Trek: The Next Generation.
Oh, yeah, Gene's Vision 2.0 definitely precedes TNG by years, but that's where it really became noticeable. It was developing during all those university lecture tours. Distinguishing himself from the Bennett/Meyer Trek was a big part of it, but the other factor was Roddenberry believing all the press he'd been getting about being a progressive visionary. His book Report From Earth was going to be a deep and meaningful look at how wonky human society would seem to an alien civilization, but the bits he trotted out during the lecture tour I saw him on were about as deep as a comedian saying, "What is it with airplane food anyway?" So the anti-military thing (and the utopian thing and the perfect humans thing) was, I think, as much about "hey, I'm a visionary and a deep thinker" as it was about "Wrath of Khan isn't my Star Trek." It's funny that the whole "we don't have money in the future" thing came from one of the GRless movies, though.