Totally redundant and unnecessary.
The purchase was for content, not new pipelines.
True, but the as the amount of content increases, so does the competition to get it into those pipelines. And as the Disney-owned networks are pretty successful with generating content in-house, they are less dependent on the need for outside material, including from other Disney divisions (i.e. Marvel).
And while Disney XD has a Marvel Block, but it's doubtful that it would expand much beyond a hour or two beyond what's currently scheduled, especially if Disney XD can fill the time with cheaper programming.
I do believe that if Disney/Marvel saw an opportunity for a Marvel-branded network in the future, they would jump at the opportunity.