You’re Leaving!
Feeling forgotten by people who are supposed to be friends can make you feel truly terrible. So, while I do feel sorry for this individual, it could have been a lot worse. These were just worked colleagues and not actual friends, so they shouldn’t worry too much about being forgotten.

They should think about the whole thing as the start of a new and better chapter in their life. It’s one where they are working at a place with people who, hopefully, actually care about them! If not – you’re at least paid to be friends with these people, which is always a benefit.