Wow. No offense Robert, but this is quite the height of supposition on your part, even more than normal. I've never heard that the production for STIII was a secret, other than the usual secrecy for any new production of anything.
Not the production, of course, but what the story was about!
I still remember vividly how Eric Stilwell (writer of "Yesterday's Enterprise" and maybe that brings us full circle?
) speculated together with many others whether Spock would be ressurected or not, and that was most definitely a big production secret and consequently the story, too. (Eric Stilwell suggested we should pay attention to the mark designation on the photorp casing and compare it with the corresponding passage from The New Testament. He was really on to something
I also remember how a lot of folks were putting pictures of director Leonard Nimoy under a magnifying glass to look for makeup residue at his ears. It was crazy.