no, because it doesn’t feel like LLM text. em dashes are neither necessary nor sufficient to make a text feel like LLM text. but they’re one feature in the classifier. if this text also had lots of “it’s not X, it’s Y” and so on, then I’d be more suspicious.
I mean, suppose for example you read the abstract of this: https://berkeleygenomics.org/articles/Chromosome_identification_methods.html
It has an em dash, and it is in a dry / boring / formal / academic / passive tone. But are you really worried it might be LLM text?
no, because it doesn’t feel like LLM text. em dashes are neither necessary nor sufficient to make a text feel like LLM text. but they’re one feature in the classifier. if this text also had lots of “it’s not X, it’s Y” and so on, then I’d be more suspicious.