I don't know if it's fair to say that these shows were never meant to be seen in anything but standard definition television broadcasts. Roddenberry tried to get Jeffrey Hunter to shoot extra footage so that "The Menagerie" (i.e. "The Cage") could be released theatrically, and many of the cast had clauses in their contracts covering theatrical exhibition.
, the Desilu series which premiered the same year as Star Trek
, actually did cut together a pair of episodes for foreign theatrical distribution (the second season two-parter "The Council" became Mission Impossible vs. The Mob