I'm using Viber and I noticed today that I am missing one contact from my Viber contacts list, although the contact is still in my phone contacts list. Does this mean that the user deleted his Viber account or that he deleted me from his Viber contacts list? Or does it imply he deleted me from his phone contacts list?
Yes, when a contact disappears from your Viber list, it means that the user deactivated his/her account. When he reactivates it back, the contact should appear again.