Thanks for that.
The Apollo 17 data user's notes do say the same thing, but on having a quick scroll through the 16mm footage on youtube there is Earth facing footage out there already, and indeed I've actually used some myself on the Apollo 17 section of my weather analysis!
The between the lines message I get is that anything that wasn't the moon was beyond the remit of the NSSDC, and as the reels they sent out were for "precise scientific investigation" rather than general or classroom use (and as film costs money to reproduce) this was why the footage was excluded.