I doubt Lucas will make the cut, but it's possible.
The only argument for this is because Lucas isn't exactly as important to the Mother/Earthbound series as Ness is worldwide. Most people associate Ness with Earthbound and that's one reason why he's still in smash bros today. Sure, Lucas is popular in Japan and that may be the only reason why he may get in.
Unless Nintendo and Itoi have plans to remake the earthbound series and for the 3DS, or in the least port each individual one to the 3DS in the same manner they do with the "3D" titles, I still hold my doubts.
The only argument for this is because Lucas isn't exactly as important to the Mother/Earthbound series as Ness is worldwide. Most people associate Ness with Earthbound and that's one reason why he's still in smash bros today. Sure, Lucas is popular in Japan and that may be the only reason why he may get in.
Unless Nintendo and Itoi have plans to remake the earthbound series and for the 3DS, or in the least port each individual one to the 3DS in the same manner they do with the "3D" titles, I still hold my doubts.