Zelalem, AMN & Akpom all had opportunities to go out on loan, Akpom is said to have wanted to stay, Zelalem & AMN I'm not sure.
AMN is the strangest imo, he had a relatively successful first season of senior football last year & Mick McCarthy said during the summer he wanted him for another season, he's stayed and like Iwobi last season been a regular in the first team training sessions. I think Wenger has a role in mind for him, last season I guessed that he'll eventually end up at RB, and he's played there this season for the reserves and it wouldn't surprise me if he does on Tuesday too.
Zelalem probably leaves on loan in January, I'm not sure what's convinced him to stay as he's spoken of his desire to play for the first team or somewhere else, he's not been around the first team at all. Elneny is gone in January for the AFCON, maybe Wenger kept him incase we're light?