Unfortunately LLMs are pretty inconsistent in how they use em dashes. Often they will put spaces around them despite that not being "correct," something that's led me astray in making accusations of humanity in the past.
0: https://www.prdaily.com/dashes-hyphens-ap-style/ 1: https://www.chicagomanualofstyle.org/qanda/data/faq/topics/H...