Continuity mistake: During the opening scene when the family is driving down the road, a newer McDonald's can be seen on the right-hand side.
Continuity mistake: The blue car gets pushed through multiple cars and is damaged. Shortly after in the same scene, the car magically appears undamaged.
Continuity mistake: When the ordered helicopters get close, there is a set of iron stairs in one shot blocking the door. A split-second later, when the door closes the stairs are gone.
Answer: I can't attest to if the end credit scene was altered, but I can say that it's been Marvel's M.O. to introduce new characters to foreshadow upcoming projects without really giving them much of an introduction. For example, Fury, Thanos, Captain Marvel, the Wasp. It seems this credit scene was meant to tease the audience for her upcoming appearance in the TV show rather than build on who they've already established her to be.
Bishop73