A lot of those memos contained jokes and gags that were surely not meant to be canon any more that a rubber duck on the 1701-D.
It's a cinch that nobody involved with producing
Star Trek back then ever thought or spoke the word "canon" at all, unless they were having a discussion about Bible study or the music of Pachelbel. That's a term that didn't become significant in Trekdom until Roddenberry's infamous TNG-era memo in which he tried to lay down the law about what did and didn't count as "true" Trek in his vision. It was only after that memo that fans began to develop this unhealthy obsession with arguing over what was "real" and "unreal" in this totally imaginary universe.
True. It probably never occurred to any of them that prequel stories would have been written. With the exception of the filmed series, the
Star Trek universe consisted of the Gold Key comics and the novelizations by James Blish.
Only until 1989 did we get the Harve Bennett and David Loughery script for
Star Trek: The First Adventure that they first start thinking about a prequel.
It probably also never occured to them that
Star Trek would have an active fanzine and fan fiction community or that some of these materials would be professionally published and rival the inventiveness or quality of licensee products.
Now we have the
Star Fleet Technical Manual and the Star Fleet Battles universe, the FASA RPG,
Star Trek Spaceflight Chronology and
Mr. Scott's Guide to the Enterprise universe, the Mastercom Data Center/
Federation Reference Series universe, the Last Unicorn Games/Decipher RPG universe, Bantam continuation novels, Pocket Book continuation novels, and comic books in addition to 11 movies and 6 television series.
Or multiple cuts of the films or a remastering of the original series with new special effects.
Or the excellent fan films
Star Trek: The New Voyages/ Phase II or
Starship Exeter.
Or the excellent web-based
Star Fleet Museum.
The expanded universe stuff is often dismissed as non-canon or depricated as "fan wank", but many of these materials made entertaining and valuable contributions to the
Star Trek mythos over the past 40 plus years.