The Husband of but one wife. That means he's never been the husband of more than one wife. Not that his wife is dead.
Paul says a bishop must be "the husband of one wife," and "must manage his own household well, keeping his children submissive and respectful in every way; for if a man does not know how to manage his own household, how can he care for God’s Church?" (1 Tim. 3:2, 4–5).
Do you interpret this to mean that only a man who has demonstrably looked after a family is fit to care for God’s Church; whereas an unmarried man is somehow untried or unproven?
Well yes, that's what is says.