I don’t agree that epinephrine specifically constricts blood vessels or airways. It can do either, depending on the situation, due to its alpha and beta receptor actions. Unlike norepinephrine, which is specifically an alpha receptor agonist, epinephrine has alpha and beta properties which can constrict or expand arteries and airways. In flight or fight situations it would be disadvantageous to restrict blood vessels and/or airways. It can help to increase heart rate as well as expand blood vessels in those situations.