Instructing Microsoft What to Do With Your Account When You Die
Microsoft does not currently allow you to decide what should happen to your account when you die. Surprisingly there appears to be no clear policy or easy to find recent information.
Outlook, Live and Hotmail accounts
If there is no activity on your account it will be deleted after 12 montshpect that no one will try to access your account, this “do nothing” approach could work well.