In the MCU, Black Widow was depicted as a very human hero.
However, in Marvel Comics, Black Widow boasts some impressive powers and abilities.
The scene would have changed the MCUs depiction of two of its founding Avengers in a major way.
The decision to cut that backstory in favor of making Bat-Seraph a former Black Widow avoided potential controversy.
The scene would have been the first appearance of the Smart Hulk persona which ultimately debuted inAvengers: Endgame.
Had the scene made it into the finished movie, it would have handled Hulks MCU story differently.