Earlier quoted context omitted.
[flagged]
I'd probably use either a semicolon or a period there. But this demonization of a perfectly reasonable English punctuation mark absolutely has to stop.
The sentence has exactly same meaning if they'd use a single "-" as well. I don't know which browsers have s where double "--" is turned into emdash, but on the systems I'm familiar with one needs to go certain lengths before an emdash appears.
Emdash does not magically appear, and it seems some people love playing with the AI connotation.