As I remember it, the use of hen came from feminists wanting an ungendered third person pronoun to use for a person of unspecified gender instead of defaulting

As I remember it, the use of hen came from feminists wanting an ungendered third person pronoun to use for a person of unspecified gender instead of defaulting to male ("han") or writing "han eller hon" (he or she). It's not exactly a new word, it's borrowed from Finnish, which doesn't have grammatical gender. So it doesn't have the "he or she" problem at all.