IMO they should go the route they did with "Rushing Attack" in the older versions.
Expand on that and keep skill players in the game and go to 7 on 7's. Linebackers, DB's, RB's, QB, WR's, and TE's. Use the interactions between actual humans to hone the animations and develop realistic mechanics to create a legitimate football experience that actually feels like real football.
OTP was a low, low priority for them. I don't think they can think creatively enough to make it work despite the fact that it's the clear money maker in other sport games.
As I said earlier; It would be insane to think Madden's developers would ever create this type of experience. Multiple dev teams have consistently proven they are not at that level for almost 2 console generations now.