You do realize that real world cats legitimately do chip, right? They have the vocal chords for it, and often use mimicry as a hunting tool in order to fool their prey. They can make both birdsong noises and high pitched rodent squeaks, usually when feeling restless or getting ready to pounce. Asking why a cat can do what cats are WELL KNOWN for doing is ... weird ... its like asking why a bunny anthro feels like hopping.
https://www.youtube.com/watch?v=YGQV6_xrLtUIf you're going to argue realism in the name of constricting someone else's character options then please make efforts to match reality, because this is getting annoying. x.x