It looks for all the world that they considered their cassette copies of the BBC masters that had been lost as the only remaining remnants. Obviously they didn't look to this forum or they would have been able to simply download better copies. Even the poor copies they have of the 1967 broadcasts show a mark of finesse in Andy Jackson's mastering. At least for some elements - noise reduction damage and other critiques aside. Point being that he wouldn't have spent that time if they had any hint that a better copy existed!
That lack of communication or reaching out is unfortunate (and rather embarrassing for them) but I do have to give them an A+ for the attitude to release the material for posterity even though it was damaged. (They truly thought they were releasing all that remained.) It appears that they wanted to include these broadcasts for completeness but they treated them as kind of an aside in that they didn't do extensive focused research or restoration.
There's really no other way to interpret it. I see absolutely no indication that they intentionally omitted anything or released substandard copies with the intention of coming back around with an upgrade (like some of the talk about the practice of releasing downgraded to CD format copies and coming back around with HD later on).