Not necessarily. There are several different types of Khajiits, some that are barely distinguishable from a cat in behavior and movement. It's not too farfetched to say that Khajiits would choose to sneak in this manner.
I'd support seeing it, it would be a cool little addition to the game. However, I highly doubt this will happen. I find it hard to believe they'd put a bunch of time into making a custom animation just for one race's sneaking.
True, multiple Khajiit types are four legged, two of the sub types who walk on two has so short legs they could walk on four with little problem however they would not work with standard clothing and armor and would require their own meshes, far more work than the sneak animation.
Only difference in Morrowind was bottom of legs and head.
For werewolf's it would be real cool and they don't use clothing anyway.