Most likely not, given its perceived status as an eventual public record [at that moment, at least], and JeffCo Sheriff Stone's general laxity with the investigation (e.g., access to Time magazine, and the Westwood pieces, fire department video, etc.).
The copycat worries, victims' rights, ownership issues with the school district and H/K families, and individual privacy concerns for this type of material were still an evolving subject.
The nearest thing to an NDA is the journalists and families were verbally warned not to use any recording devices (microcassettes, for that era) during the limited viewings. I think we know by now that some still did.