Based on this question that was asked Breaking a "engagement" (shiduch)
Has anyone come across of an idea whereby if someone got engaged and want to call it off they get married and get a Gett.
Mi Yodeya is a question and answer site for those who base their lives on Jewish law and tradition and anyone interested in learning more. It only takes a minute to sign up.Sign up to join this community
It is brought in many places in the name of the Vilna Gaon that it is better to get married and get divorced than to break off an engagement. This is often understood to only refer in a case where they performed a kinyan tenaim, which is a formal agreement to get married.
One source that brings this Vilna Gaon is Shulchan HaEzer 2:20, quoting the sefer Sha'arei Rachamim. It says the Vilna Gaon is citing sefarim, which tends to refer to Kabbalistic books.
However, I want to stress, that I don't know if anyone halacha lema'aseh says to do this. Everyone should always ask their Rav, but my impression is this language is simply to express the severity of the concept of breaking off an engagement. I'm not sure if it was ever done in practice.