I think the new Starscream transforms back-to-front compared to the old toy.
On the last toy, the cockpit slid up from the front of the plane to the back of the plane, which meant the front of the plane was the bottom of his torso. On this toy, it looks like the back of the plane is the bottom of his torso, with the cockpit just turning around. You can see his vertical stabilizers/rear tail fins folding in half and down to become his crotch plates.
Whomever posed the legs in these box photos pushed his double-jointed knees down too far. Starscream's design has a more upright stance than that.
It's possible TakaraTomy will just release Hasbro's stuff again.