And there's no reason it couldn't have happened. Filmation did two different Batman cartoons, one in '67 and one a decade later. And in the late '70s/early '80s they did new animated versions of their live-action characters Isis and Captain Marvel. Not to mention that they revived Fat Albert
once or twice after years of reruns, and did Gilligan's Planet
as a sequel to The New Adventures of Gilligan
Around the time in question, Filmation was doing the fantasy series Flash Gordon
(sort of a prototype for He-Man
) as well as animated versions of The Lone Ranger
. A new Star Trek
could've fit in reasonably well.