I recently installed whatsapp and noticed that my therapist was on my list of contacts. The next session I asked him to block me, not because I would be tempted to contact him on there, but to preempt him blocking me and getting my feelings hurt. He thought my request was really interesting and wanted to explore it further. I told him it was simple. I'd rather him reject me on my terms than on his. Like you, I would definitely check his online status if it was available to me. We once did a video call over Google Hangouts and I could see his online status for several weeks after and found it comforting. Then he blocked me and I felt really hurt. I understand why he did it, but it still hurt.