The final possibility is that Loki's planned live-action series won't resurrect the character at all. As we said earlier,there is no indication of when, exactly, the events of the series are supposed to unfold, and with the Asgardians and frost giants living for millennia, the series could be set at any point across the MCU's timeline.
The concept of playing across unseen periods of MCU history isn't unprecedented; Agent Carter, which was directly overseen by Marvel Studios execs Louis D'Esposito and Kevin Feige, was set shortly after 2011's Captain America: The First Avenger and before the 1950s archive footage of Peggy Carter seen in 2014's Captain America: The Winter Soldier. A Loki spinoff series could similarly take place either before Thor, or the involve character's whereabouts between the 2011 film and his reappearance in The Avengers, possibly even showing the origins of his tenuous alliance with Thanos.
Ever since his arrival in theaters seven years ago, Hiddleston's Loki has been one of the most beloved characters in the MCU defying death both on screen and behind-the-scenes due to strong, positive fan response. Across the entire Thor trilogy and the first and third Avengers films, audiences have followed the character as he lies, cheats, and generally deceives the characters of the MCU in his lifelong ambition to prove himself worthy to the throne of Asgard and just generally stir up all manner of trouble along the way while maintaining that defining love/hate relationship with his adoptive brother.
In the meantime, the next appearance of the Marvel God of Mischief will almost assuredly be in May's Avengers 4, though the exact capacity of his return, be it temporary or permanent, is still unknown. But with a live-action miniseries starring the character in active development by Marvel Studios, with Hiddleston confirmed to reprise his fan-favorite role, we do know, at least, that Avengers: Infinity War was not the final appearance of Loki in the MCU.