I'm sympathetic to this line of reasoning, but “LLM can play chess” is overstating things, and “despite not being trained for it” is understating how many chess games and books would be in the training set of any LLM.

While it's been a few months since I've tested, the last time I tested the reasoning on a game for which very little data is available in book or online text, I was rather underwhelmed with openai's performance.