Cobras don't work so great in the exhibit system cause their most striking feature - the hood - isn't usually stretched when these snakes are in a calm display. For this reason chameleons are more visually interesting to PZ than cobras.
It only has to rear in some poses. If it doesn't do it at all, then yeah, it's not going to be worth it. Being a video game, the interesting behaviours are significantly more common than reality for pretty much all species.
I would say the same deal for an Eastern Hognose, it just has to be playing dead in one or two poses to be that little bit more interesting. Same deal for a Tokay Gecko, if it's not on the glass at all then it kind of defeats the point a bit (
the giant snail can, so I wouldn't think that's an issue).
Just saying, I already think that the exhibit is King Cobra because I know that it resembles India with its scenery pieces and a poster made of it. Literally no sense to add something that's not even in the game.
It says King Cobra, but the design is closer to an Indian Cobra. King Cobra has a less defined hood and doesn't have eyespots on the back at all.
In any case, they're 5 year old props, if it were something they were keen on for that reason, it seems like it would have happened a little earlier (
South-east Asia namely, but there's Wetlands, Tropical, and even Eurasia that could've gone for a King Cobra)