Hey 388
Sorry for the late response. I saw this a few days ago and didn't take the time to answer.
I don't think, those are bots.
There are a few occasions where old friends gather to play this game.
Often you see such winter events when someone at work suggests to play CTD together as binding exp for the holidays.
Also there is at least one teacher here, that let's his students play CTD before holidays. I remember when I was a student, that we sometimes could play games in IT-lessons. More often than not it was just minesweeper. But I have spoken to one teacher while playing, that he uses CTD in classes.
So that's my prediction what happened.

Have a nice rest of the year!