Hi @Agustin Barto ,
Currently there is no way to get the iCalUid of a deleted events using Graph API. When an event is cancelled it is deleted from the calendar. So there is no way to list deleted events and there properites.
you can submit a feature request idea via this support link to suggest tweaks to the document content, which will be monitored by Microsoft team and make the enhancements to Microsoft Graph APIs. I will also upvote for you.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".