Been thinking the matter over a bit, not in terms of what the plot could be for a potential 2000 film, but rather the broader implications for the franchise as a whole if they had done one. I'm guessing they would have approached such a film as just another TNG film rather than potentially the last TNG film like they did with Nemesis. Meaning they don't end the movie with Data dead and the others splitting off on their own. But the film still underperforms at the box office, it ends up being the last TNG film anyway.
Yeah. The Paramount bean-counters would pull the plug on the film franchise. It would have cost more than Insurrection and the box office return would have been somewhere between $50 and $100 million, because that's where the films landed for twenty years. Nemesis didn't kill the film franchise. The costs of making the films relative to the potential returns killed the film franchise.