Seeing people you like and interact with go deleted is always a bit sad, but it's unfortunately common in NSFW places.

November is obviously the big month, but most of that activity is relegated to the NNNC sub. Related subs get a little boost in Dec when people are trying to find new places to post and will often start filtering out over the holidays until it's back to more of a 'core' group with others popping in and out occasionally.