That would be really strange since the Hebrew theophoric prefixes and suffixes in names occurred LONG before the 13th century lol...That's the generally agreed upon theory.
From what I can tell based on what I've read and through my cursory looking around, is that the oldest attested use of "Jehovah" is from the 13th century, where we find the use of Iehoua in Latin, and Anglicized by William Tyndale as Iehouah. With the advent of 'J' and standardizing and differentiating 'U' and 'V' gives us with the modern Anglicized "Jehovah".
And it's true, if we take the letters of the Tetragrammaton and use the niqqud for Adonai, we get Ye*HoVaH, which would be Latinized as Iehoua/Iehova.
*The vowelization of the niqqud here would be an "a" sound following a glottal consonant, which is the case for Adonai; but an "e" for other consnants, such as the Yod in the Tetragrammaton. Thus YeHoVaH rather than YaHoVaH.