Sakurai did a similar thing with Roy in Brawl. There was a song entitled: Roy's Hope
As it stands though, cutting Wolf was foolish. He is a mainstay to his franchise and is probably the most important Nintendo character outside of Mewtwo that has ever been cut from Smash Bros.
There is little excuse why Mewtwo and Wolf did not return.
Ideally, I would want ALL of the veterans back, however, Mewtwo and Wolf are at least iconic to their respective franchises and still relevant to them.
I would have easily traded the Clone Trinity for either Wolf or Lucas.