https://queen-erika-the-songful.tumblr.com/post/162882630705/classical-music-used-in-barbie-films

• Symphony No. 6 (Pastoral) by Ludwig van Beethoven - Movement I: Happy Arrival

• Symphony No. 6 (Pastoral) by Ludwig van Beethoven - Movement III: Merrymaking

• Symphony No. 6 (Pastoral) by Ludwig van Beethoven - Movement V: Shepherd’s Song

• Symphony No. 94 (Surprise) by Franz Joseph Haydn - Movement II: Andante

• Symphony No. 1 (Classical) by Sergei Prokofiev - Movement IV: Molto Vivace

• Edvard Grieg - Peer Gynt: In the Hall of the Mountain King, Op. 23, No. 7

Oooooh XD

I created an account just to respond to this question, because I was thinking the exact same thing!! I thought I was hearing Theme of Love and tried to find if Uematsu sampled something from classical music, but nothing seemed to match up. This Barbie movie was released before FFIV, though, so maybe it's just a coincidence that they sound so similar. I doubt Uematsu was watching Barbie movies haha.