>>715745664
Her gun has the Arius latin words in it, the complete phrase too. She was 100% going to be the traitor. However, at some point, they must have rewritten Vol3 and introduced Azusa very late into it.
But, and this is more of a guess, they had already done and completed the early game. Including the prologue, where Suzumi was there. Perhaps that betrayal was meant to be more personal, since she'd also be stabbing Sensei in the back? Anyway, they didn't want to completely scratch Suzumi, so they just put her on a club by herself and forgot she existed.

>>715366389
>I guess the retcon now is that
Suzumi doesn't show up anywhere, has no exposition, does nothing. Literally forgotten about beyond the prologue.