we see these threads, and time and again I say the same thing.
It's good to have 'closure', but that's not why we're here, and if anyone thinks that nagging people will produce the result they want they are in for a disappointment. It's a fact of life that many people simply want a quick resolution, and they move on. They don't think about thanks or acknowledgments, in the same way that they don't give you any sort of acknowledgment when you stop and let them pass in a narrow road.
If you are going to worry about such things you'll go to your grave being dissatisfied.