At the past Comic Con, Marvel Studios closed Phase 3 of the MCU with Avengers: Endgame. Of course, new productions arrived for Disney Plus, like "What if?", the series that will address the community's craziest theories.
On the other hand, Loki will be about the story of Thor's brother. Unfortunately, the producer has not revealed further details of the plot. Some believe that it will touch on past events, while others believe that it is about the future.
However, all of this will depend on whether Loki is still alive within the MCU. In Avengers: Endgame, it was seen that he managed to escape with the Tesseract, so a new timeline would have been opened.
Actor Tom Hiddleston attended The Late Show where he gave certain statements before filming the series: "In the years since Avengers: Infinity War and Avengers: Endgame, which were released in the spring, two questions have been asked of me: Is Loki alive, and what will Loki do with the cube? This series will answer both questions", he declared.