> I'm not sure why these would be just getting release by National Archives now, perhaps as a distraction?

Maybe, or maybe they wanted to avoid giving the content unearned credibility through concealment. The easiest way to turn a mystery into a nothingburger is to release it to the public.

> ... there's a lot of discussion that these photos may have been a hoax.

Yes, or sightings by people constitutionally unable to distinguish Venus from a UFO.