These seem like the kind of top-level links in a large organisation that will lead to nowhere, but I'll at least give them a try, thanks!
Now, Microsoft does not necessarily have to tell you exactly what of your data was leaked. They probably do not know! In this case, they may just respond to your request with all of the personal data they hold.
The law just says that they have to notify you of the "nature of the personal data breach as well as recommendations for the natural person concerned to mitigate potential adverse effects".