Someone from my district got a LOA, a nom from out senator as well as one from our MOC and was appointed a couple weeks ago. Would he still be the MOC slate winner even though he got a nomination from our senator?
No way to know to whom he was charged. It's a very complicated process and appointees can be shuffled around in terms of to whom they are ultimately charged (doesn't affect their status at all).
I think I saw this elsewhere: the people who don’t win the slate but still have a nomination are then selected out of the national pool. Is that correct?
If you have a nom and don't win your slate, you are sent to the National Pool from which you may (or may not) be selected for an appointment.