The only thing there that seems like it's relevant is the finding that the models they used had worse results when prompted in Chinese than when prompted in English. But ...
I am fairly sure I would do substantially worse work if I had to do it in French rather than in English, even if the work itself was all mathematics and programming and the like. Maybe that in some sense indicates that I am a stochastic parrot but it clearly doesn't indicate that I'm a stochastic parrot in some way worse than human beings are since I happen to be a human being myself.
... so what am I missing, that makes the models' worse performance in Chinese an indication that they're stochastic parrots in any interesting sense?
(I take it that "they're stochastic parrots just like we are" is not a very interesting sense. I mean, actually it would be quite interesting to understand better how much of human thinking can be reasonably described as stochastic-parroting -- fairly clearly the amount isn't zero -- but I think it would be interesting as a finding in human psychology, not as a fact about LLMs.)