That's right.

It's tempting to assume that "Inter Diabolus et Virgo" had a tune in 1450 because there are many trad variants from later centuries fitted with various tunes. A poem confined to a 15th C. manuscript would be unlikely to develop a tune later.

However, as is true of so many things, we really don't know.

Sidelight: the Latin of the title ("Between Devil and Maiden") is clearly ungrammatical. Whoever gave it that title seems to have been a real neophyte in Latin: a teenager perhaps?