Avengers: Endgame brought back the Ancient One from Doctor Strange as part of a storyline to retrieve the Time Stone, but the encounter would have been a lot more unpleasant if the original idea for the scene had been used.
Avengers: Endgame features a time travel heist, as the surviving members of the team need to travel to different time periods in order to claim a new set of Infinity Stones, as Thanos had destroyed the originals. A group of Avengers travels back to 2012 in order to revisit the Battle of New York. Bruce Banner is dispatched to the Sanctum Sanctorum in order to meet the Ancient One, as Stephen Strange had yet to become the Sorcerer Supreme. Banner manages to convince the Ancient One to let him borrow the Time Stone in order to save the people who had removed by Thanos in his timeline.
The quest to claim a new Time Stone was relatively simple, but it was almost a lot more dangerous. In an interview with Canada.com, screenwriters Christopher Markus and Stephen McFeely talked about their work with the MCU, including writing the script for Avengers: Endgame. They were asked about any ideas that they had for Avengers: Endgame that they liked but were unable to use and Markus discussed a very different concept for the Time Stone heist.
"At one point, we had a different way of getting to the Time Stone which involved some characters breaking into (Doctor Strange’s) Sanctum Sanctorum and being pursued by all the weird stuff that happens to be trapped inside there. It was totally off story and unnecessary and it got cut, but it was fun to write."
It seems that the original idea for the Time Stone heist would have involved breaking into the Ancient One's home and stealing it, rather than a brief conversation that resulted in it being handed over peacefully. It's possible that Banner would have had to face magical foes against whom brute strength would not have worked, forcing him to try and think his way out of the situation. The fact that the time travel heist already consisted of several storylines would have made this an easy one to trim, especially as the others were more relevant to the overall plot of the film, such as Thor reclaiming Mjolnir.
The script of Avengers: Endgame underwent several revisions during pre-production and a lot of potential ideas were left on the table. The producers and writers of Avengers: Endgame have revealed some of these cut ideas in the months since the movie's release, such as all of the victims of the snap being summoned to Avengers HQ straight away to fight Thanos, the reveal of Captain Marvel being purposely obscured at the start of the movie to hide the identity of who found Tony Stark, Captain America leaving the '70s without seeing Peggy Carter, and Cassie Lang attending Stark's funeral. Avengers: Endgame acted as the ending for an entire era of MCU movies and there were a lot of potential characters and storylines that could have appeared, but there was only so much time in the film, which meant that the Hulk's adventures in the Sanctum Sanctorum had to be cut.