The Loki Disney+ series is still largely shrouded in mystery, with little details surrounding the contents of the show being known at this point. From the initial Disney+ "Big Game" spot, the only thing that could currently be gleaned from the series was that the Time Variance Authority, an organization involved in keeping the timeline and referenced by a 'TVA' logo on Loki's jumpsuit in the trailer, may have some involvement. Rumors have also circulated about the possibility of multiple versions of Loki's being featured, such as a female or kid Loki, however these have not been fully substantiated as of yet. Now, a new rumour is circulating, which may give a better indication as to where Loki is leading...
According to Daniel Richtman via Full Circle Cinema, a Squadron Supreme project is rumoured to be in development, with the once super-villanous turned superhero group reportedly set to make their MCU debut in the Loki Disney+ series. It's said that this will lead into the team jumping over to their own property, although it is currently unknown as to whether this will take the form of a series or a film.
WHAT THIS MEANS
The Squadron Supreme initially made their comic debut under a different, more evil moniker: The Squadron Sinister. This comprised of a team of supervillains including Hyperion, Doctor Spectrum, Nighthawk and Whizzer. Another version of the group from a parallel Earth later returns as The Squadron Supreme, all with the same names, which confuses the Avengers and causes the two teams to battle it out.
It is currently unknown what adventures Loki will get up to in his series, but rumours of him assembling his own supergroup of Loki's points to the idea of possible parallel universes via the Tesseract/Space Stone, which could be the way in which Loki finds himself in contact with the Squadron Supreme. It's possible that the Loki series will be tracking the group's odd positioning as both a villanous and heroic group, and will portray both versions by visiting different versions of Earth.
Tying into the further reaches of the MCU, Hyperion is also the last Eternal left on his version of Earth, so its possible that the both Loki and the Squadron Supreme project could tie into The Eternals in some form.