Why not, man? Why not bring back one of the coolest, most capable members of the Rebel Alliance? By all accounts, he survived the events of the original series, having served as a crack pilot in several assaults on the Empire. After rising through the ranks of the New Republic and floating in and out of retirement, Wedge eventually offered his services to the New Jedi Order and one of his besties, Luke Skywalker. So there's a built in excuse for him to appear in the movies right there. Honestly, it would be a little bit strange if Wedge wasn't a significant character in the story, considering his close relationship to the main characters from the original film and his relevance to the new society they have worked to establish. Although Denis Lawson has reportedly rejected offers to appear in the trilogy unless it was in a more prominent role, the future isn't set in stone. He could change his mind for the next two films, or they might take his idea seriously and make Wedge a more significant figure later on in the trilogy.