Yes, the F-111 lost it's Navy mission, but not it's Navy baggage. It kept the TF-30 engines that would cause interesting problems for the F-14 too. Navy aircraft have to be serviced in their shadow so there was a complex set of maneuvers required to remove an engine. Since an airbase has acres of space it's much easier to remove the engine, just roll a cart up, unplumb the engine and slide it onto the trolley. A seasoned crew can remove and replace an F-16 engine in 30 minures or less.
Grumman built the tail section of the plane and absolutely would not remove any weight. GD went to the extremes of replacing EVERY steel bolt with titanium ones. GD removed so much weight that the plane was wildly out of balance, they had to mount a 65 lb block of expended U-238 to the back of the front bulkhead to re-balance the plane.
GD never did figure out how ro adjust the wing glove and inlet geometry to handle the aerodynamic issues caused by the swing wing.