The TVA assigned with the task of preserving and prevent the creation of any major branching of timelines. So, Thor stealing the hammer from another timeline in Endgame wasn't that 'important' branching

The hammer was returned, just like the stones were.

They also only defined important as timelines that lead to different versions of Kang.

Thor did not become hammerless in the 2014 timeline, the moment Thor and Rocket left, Cap arrived and return the reality stone and mjolnir.

I would love to see how did He returned the reality stone into Jane

Why would they? Nothing in there to suggest HWR wouldn't be born.

Even if it wasn’t returned, the TVA were only focused on pruning timelines that caused a Kang variant.

In all fairness, did they ever expect anyone else to be able to get Mjolnir?

With that in mind could anyone be able to handle mjolnir in the TVA? Magic has no use there to the point where infinity stones were just regular stones but shiny...

The things they took were returned to exactly where they came from thus cutting the branches

A. It was returned B. They basically say all the Avengers stuff was “supposed” to happen.