When Marvel's Phase Four kicked off it wasn't entirely clear where everything would be set on the old timeline, and now thanks to Loki there is frankly any place on the sacred timeline that any film or show could happen. With Black Widow starting the latest wave of feature films, and being set between the events of Captain America: Civil War and Avengers: Infinity War, it seemed like Marvel Studios might be interested in playing with the timeline but now we know they're pushing things forward fast; Shang-Chi and the Legend of the Ten Rings director Destin Daniel Cretton confirmed the film is set in the present with the final trailer for Eternals revealing its place as well.
Cretton told Fandango earlier this week that "Shang-Chi is set in the present day in the MCU timeline," giving further confirmation ("Yeah, yeah") when asked if the film is definitely set in the post-Snap "present day" of the MCU. Notably in today's Eternals trailer came the reveal that it appears to be set almost immediately after the events of Avengers: Endgame. As the trailer begins, Salma Hayek's Ajak speaks to Richard Madden's Ikaris, noting that Thanos snapped away half the universe "five years ago" but that the people of Earth were able to bring them all back with the snap of their fingers. She further cements how soon this exchange is happening after Endgame's final scenes though, noting that the sudden return of all the people on Earth has given the planet enough energy for "The Emergence" to take place, and they only have seven days.
As fans may recall, Avengers: Endgame picked up almost immediately after the events of Avengers: Infinity War but jumped ahead five years in time to the year 2023. Knowing that, and knowing that Shang-Chi and Eternals are taking place in that aftermath we can pretty confidently put them at similar points in the time line and just after the events of Endgame. How these two films potentially rub up against the placement of Spider-Man: Far From Home is unclear since that movie also took place in the aftermath of Endgame.
With more titles than ever on their release schedule Marvel Studios will need to be cognizant of timelines in their releases, naturally the COVID-19 pandemic forced plans and release dates to be shifted and changed which perhaps will make things more difficult to place as being one after the other.