I don't know how many tribute videos had aired on mainstream news television stations previous to this one, but I'm going to assume that this is one of the more in depth ones . I think NBC decided to air it in 1995 because it was 50 years since the bomb was dropped. This provided an 'anniversary', except in the negative connotation. It seemed to me like NBC was trying to take the blame off of the US, almost. I got that feeling from the news casters "post note", in which he talked about how the US has decreased its nuclear research as well as their nuclear production. They also had a veteran who talked about how many people they may have saved by dropping a nuclear bomb.
On the other hand, they did focus a lot on the survivors stories (from the Japanese perspective), which seemed to balance it out. As a final note, I still think that NBC did not dwell enough on how this bomb added to the US's pending imperialism. The US essentially bullied the Japanese into surrenduring, making the "ends justify the means", and doing things "for the greater good".