This was confirmed by another dev (not Spellchecker) as something that couldn't be added due to time and/or labour constraints. So it's not a bug.
Going forward I don't think we're going to see it updated... ever. They'll always have more important things to do and most players are probably desensitized to it. Not to mention, since the decor is no longer available, it wouldn't make Carbine any extra money to fix the cadets.
Maybe, if we're lucky, there'll be a fix next time Space Chase comes around. But I have doubts.
Until the day Carbine has the resources to make animations for the various models that are being released as statues, please folks, stop calling them NPCs! Just call them statues or do what I'm doing... use/sell them as action figures. Collectibles advertised properly can have just as much value as animated NPCs.