The Black Widow, Smart Hulk, and The Falcon scene were deleted from Avengers: Infinity War. But now the scene is back with a bang, online. It will be used for the purpose of introducing Natasha to Smart Hulk. The character was eventually introduced in the follow up of Infinity War, Avengers: Endgame.
There is no denying the fact that the fan following of Infinity War is enormous. Fans tweeted that they were eager to see the transformation of Smart Hulk in the final film. This one lack total effect and for a major part portrays Mark Ruffalo not in the form of the Fuming Green Giant, but in motion capturing suit.
This would have been the perfect finish.
Fans also expressed their desire to watch Thanos vs. smart Hulk at the end.
The whole concept behind the particular scene in question as a reverberation of a comparable scene in Avengers: Age of Ultron. Here Natasha was seen trying to desperate attempts of calming down after a fight.
Now this is where, things changed when she came to the realization that there is no need to calm down anymore. The Hulk and Bruce Banner sides of his character have combined.
In lieu of this disclosed delay, Banner spent the complete Infinity War making desperate attempts to persuade Hulk out. And was ultimately forced to put on the Hulkbuster shield, in the climactic battle of the film.
The decision to delete the scene was brought into limelight by writers Stephen McFeely and Christopher Markus. According to them, it was a lot of fun when Banner transformed to Smart Hulk, but it was not at the right moment. This took place in Wakanda. The design of the arc was not really getting along well with the hulk character. Things were changed and there was a transformation to Smart Hulk.