Jeremy Renner wasn't informed where Clint Barton's family went in Avengers: Infinity War, Hawkeye came back to the MCU with a brand new persona - Ronin. Born out of the tragedy of losing his whole family from Thanos' deadly snap, it took a while before he banded back with the rest of Earth's Mightiest Heroes in the hopes of bringing back everyone who died during The Decimation.
Endgame is the culmination of everything that transpired in the MCU since it began in 2008's Captain America: Civil War, Hawkeye was utterly confused when all the of his family disappeared into thin air. Renner effectively conveyed what Clint was feeling at that time as he clumsily roamed the area to find his kids and wife, and it turns out, part of the reason why is that he wasn't informed where they actually went.
Appearing at Celebrity FanFest in San Antonio over the weekend, Renner recalled filming that scene, saying that he was genuinely unaware where Hawkeye's family supposedly went. At that point, they were filming back and forth for Infinity War and Endgame, so no one knew about The Decimation yet, and although the actor asked, they refused to tell him. He eventually realized for himself what was happening and Renner its that working on that part of the movie messed with him. Watch the portion of his where he talked about the matter in the video shared by Patty G on YouTube below:
With Hawkeye reunited with his family following the successful Time Heist, it's curious what Marvel Studios is planning for the character's future in the MCU. There were rumors that he is getting his own Dinsey+ TV series like the God of Mischief in Black Widow standalone flick.
The aforementioned scene was filmed in a way that emphasized Clint's rising panic not knowing what happened to his family. The shaky camera and facial close-ups gave it a sense of urgency that made it a bit difficult to watch. It was a great way to ground Avengers: Endgame considering that much of its story dealt with non-existent concepts such as Time Travel. Fans never saw Clint until five years later when he finally assumed the role of Ronin. Not much is known how he transitioned from a grieving father to a ruthless samurai, but if Marvel Studios want to explore that time-period, looking at the tragedy from Hawkeye's perspective would be an interesting premise.
Source: Jeremy Renner (via Patty G)