Disclaimer: I'm EF about 99.9% of the time, but occasionally do an OF, usually in Latin and ad orientem, and very rarely an OF in the vernacular.

For the Propers, the Graduale Triplex (which I assume is from the GR), shows these choices for the votive Pro Sponsis (bolded choices equal EF Proper):
Introit

• Deus in loco sancto suo
• Domine, refugium factus es nobis
• Timete Dominum, omnes sancti eius

Gradual

• Timete Dominum, omnes sancti eius
• Uxor tua

Alleluia

• Mittat vobis

Offertory

• Immittet angelus Domini
• In te speravi, Domine

Communion

• Beati mundo corde with ps. 33
• Primu quaerite regnum Dei

As for the Ordinary, Mass VIII (de angelis) is suited both from the general classification and from the fact that of the Masses in the Kyriale, it is likely one most recognizable to those attending. Usually, Mass VIII is the the choice for most OF nuptials we are asked to sing. As regards "appropriateness", the Kyriale is extremely fluid. Most Masses are appropriate under most circumstances. I wouldn't do Mass I outside of Paschaltide; I wouldn't do Mass XVII or XVIII outside of Advent or Lent; but other suggestions regarding the use of particular Masses are merely suggestions (i.e. not rubrical) and have changed at times. Mass XV was once recommended for "simple Masses" - now is recommended for "Christmas season" as an example.

Why is that?

When Solesmes was commissioned to produce their first official Graduale, it was only an interim work. The 1961 GR is based on the 1908 edition produced to meet the need identified by Pope Pius X as quickly as possible*. Thus Sacrosanctum Concilium 117 :

117. The typical edition of the books of Gregorian chant is to be completed; and a more critical edition is to be prepared of those books already published since the restoration by St. Pius X.
It is desirable also that an edition be prepared containing simpler melodies, for use in small churches.

The revision allowed the restoration of ancient chants which had been dropped from the repertoire, and the removal of inauthentic later compositions. GR1974 also takes advantage of the greater variety of texts in the OF, and the revision of the calendar.
*When it was commissioned the monks were already living abroad, having been expelled by the French Government (for the fourth time in 30 years). Since their return the work was further delayed by two World Wars!

In this case of the propers for the wedding Mass, the "new" propers listed in the OCM / 1974 GR are all chants that were present in the 1908 GR to begin with. They are just rounded up from diverse other occasions.