Unless they have a way to assign it then reassign it. Trying to think more like a regional airline scheduler and not a mainline carrier one. But I've seen WS's here assigned to a regular line holder, which sucked because I had a yellow slip in for it, and then 6 hours be reassigned to another reserve pilot, who was not me because they gave me the trip I was originally trying to avoid via the yellow slip for the better one.

Not saying that was anything dirty, just saying trips can go away and pop back up.