Yep, Ultimate Providence is actually part of the "Solemn" Counter Trap cards, since its Japanese name is "Kami no Setsuri" ("God's Blessings"), which uses the exact same "Kami" as the "Solemn" Counter Trap cards.
Anyway, if the OCG branch ever released a support for the "Solemn" Counter Trap cards, thus turning it into an archetype, TCG branch would have to either rename Ultimate Providence, or give it an archetype clause to make it part of the archetype.