Let's talk logistics of this concept.
So let's say there IS a litter box in the bathroom. Is it in a stall or in a corner by the sink? If it's not in a stall, do the kittykids pop a squat and drop a deuce out in the open with the other kids watching? That wouldn't cause any kind of an uproar, and certainly wouldn't result in any bullying.
If it's in a stall, does the stall have a door? If not, then they're still fudge squirting in view of other students. Also, unless it's a handicap stall, then "normies" would have to step over the litter box to use the toilet themselves most likely. No chance they would complain or perhaps post on social media.
Since they think they are cats, do they cover it up? I know when my cat rolls a cigar there is scratching for several minutes, to the point we've had to put posterboard up around the litterbox because he was scratching the fucking wall trying to cover his treasure. Surely a good furry would want to cover their tracks like a good feline.