My theory on this. Even though these people were adults. And you thought you they were going to their own homes. They didn't, and the Grim Reaper came and now they have to haunt you until you retire. 😂
Seriously though, I think the game sees the moving out option for adults as the same thing as retirement. This is why they are grayed out and you can socialize with them. They sometimes periodically walk down your street though. When this happens I think you can talk to them.
None of my retired Sims walk down my street or the Sims I move out.
Once I retire them, they are gone never to be seen or heard from again.
As for the moved out Sims, I can socialize with them via the communication's tab only.
This was my first Sim's daughter to move out and now the other sons and daughters can not get to know her.
Oh well.
Maybe someone befriended her and then retired her.
Never know since they become NPCs.
