> A curious example of a Germanic cousin of English that underwent the same "masculinization" of the word man but "came back" is Swedish, where the word "man" means "adult male", but is also used as a neuter pronoun meaning "generic person" (usually translated as "one" in English).

We sort of have this in English too: "That's one small step for a man, one giant leap for mankind". Although I can't think of any cases where we use "man" alone to mean "one".