Yelena Belova: OK, you got a plan, or shall I just stay, duck, and cover?
Natasha Romanoff: My plan was to drive us away.
Yelena Belova: Well, your plan sucks.
Natasha Romanoff: How many others are there?
Yelena Belova: Enough.
Natasha Romanoff: Here's what's going to happen.
Melina Vostokoff: Natasha, don't slouch.
Natasha Romanoff: I'm not slouching.
Melina Vostokoff: You're going to get a back hunch.
Alexei Shostakov: Listen to your mother.
Natasha Romanoff: Oh my God, this.
Alexei Shostakov: Up, up.
Natasha Romanoff: All right, enough! All of you.
Yelena Belova: I didn't say anything, that's not fair.
Natasha Romanoff: Before I was an Avenger, I made mistakes... and a lot of enemies.
Alexei Shostakov: We're family. We fight with you.
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