Recently a rumor came out about the Loki series that said that he would not appear in the show but instead only narrate it. That now appears to be false!
In a THR article about the writer of Rick and Morty penning the series, they describe the plot as:
“Sources say the show will follow Loki as the trickster and shapeshifter pops up throughout human history as unlikely influencer on historical events.“
Sure, it could be a prequel. But how cool would it be if Loki is jumping through Quantum Realm Time Vortexes?