Contacted opponent a week ago (Feb, 4th), but they have not been online since they registered for OST (Jan 9th). (their "in" post is literally the only thing they have done at smogon forums). I believe it is safe to assume that they will not be playing.
I messaged my opponent's user page at the start of the round but they said they would get back to me later because they were sick at the time. They never got back in contact. I sent a reminder message on the post this week but they have not responded.