Possibly would be my best guess. USNA seems to have a disconnect between portal and snail mail updates- when my medical status changed it was over 2 weeks until I received paper-mail correspondence. I live in MD and received the WL notification last Monday- no letters as of yet.
If a portal says turned down but you email states " however there is a NWL of 150 " does that imply you are on NWL? So vague