Even in a Smash context, Disney is the only copyright listed on Sora's Challenger Pack. Nothing about Square-Enix like Sephiroth, the FFVII costumes, the Geno outfit, Hero (along with Armor Project, Bird Studio, and Sugiyama Kobo), or the Dragon Quest costumes (also along Armor Project and Bird Studio; Sugiyama Kobo is only listed for Hero, probably in relation to the music he comes with).
Funny enough, the copyrights specify Final Fantasy VII and Super Mario RPG while not any specific Dragon Quest title.