Well file this under unexpected news.
The official twitter account of the Mana series ahs posted a ten second clip of Seiken Densetsu 3 running on the Switch.
#???? pic.twitter.com/uXD0hey02H
— ???? -??- (@Seiken_PR) March 20, 2017
This could be for the upcoming Switch virtual console but the fact that there is border art seems to signify something else. Could this be aport instead of a virtual console re-release? If so, hopefully it gets localized for the west. This is a game that has long been desired outside of Japan.