I know that page startrekhistory.com has been around for a while. In going to the Wayback Machine Internet Archive, the current version of the page seems to have been posted on line since October 10, 2011. If you go back to September 25, 2011 (which is the last time before
October 10, 2011, that that particular "City on the Edge of Forever" page was archived), you'll see that the page doesn't
have those sound clips. The sound clips do show up starting October 10, 2011. That is of course, a year before the LaLaLand set was released.
For what it's worth, Star Trek New Voyages
has had the entire music collection from TOS
for years. (It's not in flawless condition like the new LLL set is, but we've had it all for years--without dialogue and sound effects. If you check out our episodes, you'll hear the use of all kinds of musical cues that had not been publically available (even on all the various CDs that have been released over the years). Folks have been begging us for years: "Where did you get the fight music from 'Spock's Brain,' and how can I get it from you?"
If we've had all this not-publically-available music for years, I suspect that startrekhistory just got it from the same source.
Archived page is here:
Are you sure that's where they got it? It could be true, but they could have also acquired it by other means.
That strikes me as improbable. As I understand it, the reels of audiotape were in Neil Norman's possession for about 25 years, and he jealously guarded them. Getting him to agree to any kind of release was one of the biggest challenges that LLL had to deal with.
The public got access to the previously unreleased music via the LLL CD set. This is not
like workprint film trims that were mailed all over the country in the 1970s.