Well, hardcore Trek
fans know that it was never really Greg Jein's theory to begin with. The idea of the Enterprise
being a "Constitution-class" started long before Greg Jein wrote about it. (I'm not sure why anyone saddles him with creating that notion.)
Scene 44 of the Second Revised Final Draft for "Space Seed," dated December 13, 1966 has the following content:
44 ANGLE ON SICK BAY VIEWER
It is covered with mathematical symbols and diagrams. CAMERA PULLS BACK to show Khan studying with great concentration. He pushes a button. Another transparency appears: a chapter heading, reading: BASIC SPECIFICATIONS, CONSTITUTION CLASS STAR SHIP.
Scenes 47 and 48 have similar content:
...At the door, she [McGivers] turns and looks back at him. He gives her a strong, masculine, confident smile. She is about to say something, but turns and exits. Khan turns back to his studying. He pushes a button, stares back up at his screen.
48 INSERT SCREEN
A chapter heading: Basic Propulsion Systems, Constitution Class Star Ship.
Although from an "angels dancing on the head of a pin" standpoint, I guess it's debatable if this actually means that the Enterprise
itself was meant to be one of these Constitution-class ships that Khan was reading about. (Personally, I think that is exactly what was meant, but certainly anyone, Greg Jein or Bjo Trimble included, could be forgiven for leaping to the crazy conclusion that is what the "Space Seed" script intended.)
And, of course, in Greg Jein's 1975 article "The Case of Jonathan Doe Starship," he mentions:
"The Enterprise is known to be a Constitution Class ship."
So, it's not like he just made it up himself. It was already "known" before he wrote about it. (In fact, he even cites "'Space Seed' Scene 44" in his article.) To Bjo Trimble's credit, shew knew as well, and even put this "fact" in her Concordance
years before Greg Jein wrote his article.
I think "he needed a ship name with a letter like A, B or C as in 'Constitution'" is a bit wide of the mark. I think Greg Jein promulgated the crazy notion "Constitution-Class" because it was scripted, not because a "C" starship would fit his numbering scheme.
I guess it's debatable about how official it is if it's in the script or is screen visible but only to a select few or only to the Average Joe 40 years later in a DVD and HD era. But I don't think Greg Jein was going out on some "pet theory" limb; he just had access to better official production information than most people did, and he was more knowlegedable on the subject than most people were.