"There are differences between men and women" isn't a fascist-coded statement because of the statement itself - it's obviously a true statement no matter what you believe. It's fascist-coded. This statement is almost exclusively said by fascists, for reasons that have not much to do with the statement itself.

Why is that? IMO it's because fascist slogans always tend to drift away from their actual meaning, towards things that are socially acceptable to say.

Back in Hitler's time, Hitler didn't give speeches about "Let's kill all the Jews" - he'd rather give speeches about "Let's clean up Germany" even though he clearly wanted to kill all the Jews. When Hitler says "Let's clean up Germany" and the crowd goes wild, you know they're going wild because they're wild about the idea of killing the Jews, not because they're wild about the idea of mopping the floor. At least I assume you would know that now, with the benefit of hindsight. You'd have to be living under a rock not to. And that's not a euphemism for "Let's kill all the Jews" specifically. It's a general euphemism for all the bad things he wanted to do with all the people. It's not like there's one euphemism for "Let's kill the Jews" and a different euphemism for "Let's gas the Jews" and a different euphemism for "Let's kill the gays". It's more like all the euphemisms point to all of the underlying true thoughts, all at once. One loose region of semantic space points to another loose region of semantic space.

You can see how Hitler could have started out saying what he actually meant, but to avoid scrutiny he'd drift towards more innocuous words, but anyone who's been following his whole campaign would know what was meant. It's a bit like Cockney rhyming slang - the pointer drifts until it has no surface-level relation to the pointee, but just because it's not surface-level obvious, doesn't mean it's unknowable (as people who pretend not to recognize the statements often claim).

And if I'm in Germany in 1932 and I'm following politics, and my friend says "I support cleaning up Germany" I'm going to do a double-take. I'm going to suspect he's not talking about mopping the floor and picking up litter. Though, if I'm in Germany in 1932 and I'm ignoring politics, I might reasonably assume that he is talking about those things and get quite confused why my other friend thinks he's a fascist.

In modern fascist dialogue, "men and women have differences" is a pointer to the semantic space containing statements like "women belong in the kitchen", which itself is pointer to the semantic space containing statements like "women should do what men tell them". You can see how this came about because saying "women should do what men tell them" would be unpopular, then fascists justified it with logic like "well women are biologically submissive and men are biologically dominant" and it over time it got watered down to stuff like "men are biologically different from women"