Marvel Studios has finally confirmed the release window of the Disney+ Loki TV series. The impending launch of the Disney+ streaming service looks set to transform the shape of the MCU; Marvel Studios is producing a range of six-to-eight episode TV shows that star actors straight from the movies. All of these series will be available exclusively on Disney+.
Marvel has hired Michael Waldron (Community, Rick and Morty) as showrunner for the Loki series. According to the official synopsis, Loki follows Thor's unruly (adopted) brother as he "pops up throughout human history as [an] unlikely influencer on historical events." The first image from Loki revealed that the God of Mischief will arrive in America in 1975, based on posters in the background. This strongly suggests there will be either a number of flashbacks, or else Loki will be traveling through time.
As part of their SDCC 2019 Hall H panel, Marvel Studios has confirmed that Loki releases in Spring 2021 on Disney+. That fits well with previous reports that the series was intended to release as part of a second wave of Disney+ content, running from November 2020 through to November 2021.
Marvel confirmed that this is the version of Loki who escaped with the Tesseract in Avengers: Endgame, which crucially means he will be a far more antagonistic character. This is the Loki who invaded Earth; granted, Marvel has since retconned that Loki was under the influence of the Mind Stone, but he's still an out-and-out villain. The mainstream Loki became a rather more heroic figure, siding with Thor against Hela and ultimately sacrificing himself in a doomed attempt to kill Thanos. Actor Tom Hiddleston has said he believes that Loki was fully redeemed in the end.
At the moment, it's still unclear whether the historical aspects of the Loki TV series will be flashbacks, or instead will involve Loki using time travel to explore human history. Surprisingly, the latter is possible; Loki could potentially have realized time travel was a practical reality, not just a theory, as a result of the events of Avengers: Endgame. If that is indeed the case, then it wouldn't be a surprise to see Loki send history careening off its tracks, and unwittingly create a few new timelines of his own. Marvel's much-anticipated SDCC panel also included the official announcement of Doctor Strange in the Multiverse of Madness, so the studio is clearly committing wholeheartedly to the Multiverse model of temporal mechanics. That means anything is possible for the God of Mischief.