This is such a grey area. Athletes get sick too and sometimes need "banned" substances to maintain a healthy lifestyle so they apply to WADA to make the appeal to take certain drugs. What people need to realise is if this was all gone through official channels then its legit, as much as we wanna hate them for it. It could be legitimate reasons and are we supposed to deny athletes drugs when they are sick? No ofcourse not.
However what comes into question is when these drugs were taken, if they were needed and how long and consistantly have they been used. None of the files leaked so far have confirmed or answered any of these questions so as of right now, there is nothing "suspicious" going on with the williams sisters. Athletes have every right to conceal medical issues as much as the rest of us and so far we have no proof that any of this was illegal or done for performance enhancing reasons. This could change in future leaks, it could not but as of when i post this. Noone has done anything wrong.