Actually, HIPPA only restrict
medical personnel from divulging
personal medical information about another individual. A non-medical observer could legally tell the news media everything he/she witnessed, even interpreting a visible electrocardiogram screen if it was visible to him/her.
NASA probably has some additional restrictions on what its employees and contractors can tell the media, which is probably the real issue, here.
But, I think that, as the taxpayers who pay for all of NASA, including the space station and the astronauts salaries, we are entitled to know what happened to an astronaut doing the work we paid for. Effectively, we are the real employers. So we need to know if our employees in NASA were negligent or if they discovered something that we need to know about as we decide how to proceed with putting humans into space.
This is not a "national security" issue, so the actual need for secrecy is not evident.
But, the way NASA is handling it provides real opportunity for malicious misinformation efforts intended to hurt our nation. That is a very real issue that does involve national security, as evidenced by the recent riots in various countries that were targeted with misinformation campaigns. For instance, see
https://www.bbc.com/news/articles/c4g2x3kr6lgo for an example of how this was done while the medical condition of the Princess of Wales was being withheld.