Solely in terms of production, it still makes no sense to me.
They had a re-design as seen on the Playmates figures but scrapped it at the last minute. Okay.
Then they scramble to get DS9 versions (why?) and even then there aren't enough for everyone and they have to borrow from other actors and some cast have to keep their TNG versions. Why bother?
If they can't outfit their cast and there aren't enough to go around, why bother? Why was it so crucial that TNG cast change uniforms, even under impractical production strains, even inconsistently on-screen?
If they were gonna keep some cast in their TNG versions anyway, then just keep everyone in TNG versions. Why would it be a problem? Who would complain or be bothered?
Did they think fans would complain that the crew is wearing the same uniform from the series IN A MOVIE?