I think Doumbia is a better central midfielder than any of Jack Price, David Edwards or Lee Evans so for that reason I'd like to see him stay on if he's willing to give it another go.
Really, with all we've learnt about the atmosphere in the Wolves camp during that season, is it that much of a surprise that a foreign signing didn't settle in and lacked fight when things were going poorly? The mood around the dressing room seems completely different to how it was, we've got a new management team, a new squad, a new style on the pitch and we've even added another Malian player in Nouha Dicko. He could well come back and do well for us.
Saying that, I do expect there to be interest from French clubs after the impressive season he had at Valenciennes.