5 characters who are likely to be removed?
-Snake - Not due to relevancy, he was never really important, but as a third party character, negotiations could always fall through, especially with Konami's increased distance from Nintendo these days (no Hundson, no ProEvo, etc)
-Falco - Wolf had more unique assets built into his character, and the only reason Star Fox had so many characters in Brawl was due to its popularity in Melee. Star Fox characters weren't that popular in Brawl and the series is otherwise almost dead.
-Lucas - Ness has worldwide appeal, and, if characters are getting cut, I think he'd go before Toon Link, Ganondorf or a second Star Fox character.
-Ike - Replaced by an Awakening representative.
-ROB - I think he could be dropped for the same reason as Mewtwo - in spite of being completely unique, he just wasn't very popular. So, if Sakurai ends up having to cut characters to finish the line up again, he'll go. Also, his moveset seemed mostly based on SSE, rather than ROB itself, so he might even have been intended to be a one shot.