Ron Moore said in an interview that his idea was that the Star Trek television continuation popularly known as "Phase 2" did actually happen in the '70s, and "The Wrath of Khan" was, in fact, the first big-screen Star Trek movie.
(Which I find intriguing, because Phase 2 was being developed with the assumption that Nimoy wouldn't come back, and Shatner might only be a regular for the first half of the first season, and become a recurring character after that, so it's entirely possible TWOK would've been billed as the triumphant return of Kirk and Spock to the Enterprise, which would've made the end even more of a gut-punch).
Since we're up to 1994 now, I imagine Ron Moore might've also decided that he and Braga got an extra week to polish the script for Generations and he caught that mistake about the "much too big" margin of error.