Why be so secretive? This is not a military mission. These missions cost a lot of taxpayer money (money well spend you may argue), but we deserve full transparency. You don't get to go to space on other people's money and expect privacy. We might want to learn from what went wrong here.
As a hypothetical example, it’s possible to disclose if this health issue was known before they were selected for the mission, and if it was, what processes were in place to determine if they should or should not go, etc, all without revealing personal health information.