Wolf NOT returning at this point... would honestly kinda surprise me.
IF we didn't get

, I would be less confident in his return. But because Lucas and Wolf, conditionally, were/are so similar... it just makes sense for Wolf to be a stepping stone on the line.
Quasi-Clones from series with one specific region being the significant majority of the fanbase, whose special moves were divied up as specials for the others in their series and ended up being cut from Smash 4.
Wolf being one of the later additions for Brawl is one of few differences I could cite, because in some extent weren't both considered for Melee? (Lucas dropped because Earthbound 64 didn't happen for him to replace Ness, and Falco took Wolf's spot because Sakurai thought Wolf and Fox would be too simlar in looks at the time?)
With Sakurai's stance on "fanservice" being a focus and Wolf being a popular cut veteran... and basically the ONE that has both popularity AND viability to return.... it just makes sense to me.
WE'LL SEE, BUT I'M JUST STATING MY LOGIC.