>>11979105
>The game later remerged as Seiken Densetsu.
They were unrelated projects. Square reused the trademark, but very little if any of the Disk System development was carried over. Square essentially chose Final Fantasy over the original Seiken Densetsu, which died with the Disk System.
Not the only time Square flipped names around, Secret of Mana was tentatively a CD game in the numbered Final Fantasy series before being codenamed "Chrono Trigger" and then became a SD/Mana game later.