Even before TNG debuted in 87, it seems like TOS reruns got a fair amount of play in syndication. I remember watching original Star Trek episodes at random hours of the day back when WPIX was an independent station carried through a wide swath of the Northeast.
The production history of Star Trek: The Motion Picture is complex.
Some background:
Almost two decades before the launch of UPN, Barry Diller tried to create a fourth major television network under Paramount's branding and ownership. "Star Trek: Phase II" was to be the flagship series for...