It doesn't need Wolf to sell, dude. Let it go already. No, nothing hints at Wolf being playable. If he does come back via DLC, awesome. If not, that sucks, but so be it.
You seriously are obsessed and looking for hints that don't exist. Move on, man. Look, he's my Brawl main and while I miss him, it's not worth going nuts over if he doesn't reappear. If you don't want to buy the game, that's fine, but there's quite a few people, even Wolf fans, who still want to because there's more than one character to the roster. Never mind there's more than characters too. The only real key thing about the characters is that the 3DS and Wii U will have identical rosters. The roster is already severely amazing anyway. And if he somehow doesn't come back, go make a Mii Fighter of him then. It ain't perfect, but it works.