unusual to list those you mentioned as potential witnesses in case they find out information that makes them want you/them as witnesses.
They’ll throw your/their names on the list of potential witnesses so they can’t prevented from calling you as a witness if your side doesn’t call you.
I don’t do tons of litigation, but I have. And I have been involved in a civil suit once as a named party. I can tell you that every time the other side files something, it’s natural to be nervous and think it’s bad or scary. In reality, the best course of action is to take a deep breath and wait a bit before getting nervous. Things are rarely as scary as they seem before you’ve had time to process them.