I think it makes you look deperate for endorsements. The story will continue being news with or without team Obama getting involved because it’s the kind of mindless story network news loves to run with. As a candidate he should either be trying to draw attention away from that red phone ad, or putting out messages to counter it.
Drawing more attention to the ad that cost you two primaries is not a good plan. The fact that the kid is now 18 and likes Obama does nothing to change the minds of voters that were swayed by the ad.