The Wii is still getting releases after 12+ years. I think we know how to end its legacy. Epic Games most likely will have to make a new engine due to the Wii's lower power than modern consoles. Also, it would be the only game left on the Wii that uses Nintendo Wi-fi connection.

A cool feature of this version would be the ability to choose your control type. You would be able to choose between the Wii Classic Controller/ GameCube Controller, having the same controls as the console versions. Or a new play style with motion controls with the Wiimote and Wii Nunchuk. Of course, the controls of the nunchuk style would be decided by Epic Games. Also, in order to get V-bucks on Fortnite on the Wii, Nintendo would open the Wii Shop Channel back up in order to release the V-buck packs.

If all of this were to come to fruition, we would be ending the Wii's legacy on a high note.