WARNING: This article contains major spoilers for Loki episode 1.
MCU Phase 4 will continue to tackle the aftermath of the Avengers' fight against Thanos which poses new challenges for the heroes that remain active in the franchise. For Stephen Strange, that's navigating his role as the future Sorcerer Supreme potentially without his primary weapon — the Eye of Agamotto.
After Thanos accomplished his goal of balancing the universe by decimating half of life in the universe in Captain Rogers' final mission before officially retiring. So officially, the Infinity Stones no longer exists in the main timeline which leaves Strange in such a precarious position as he continues his responsibility as the leader of the Masters of the Mystic Arts.
It's already been hinted at that somehow, the future Sorcerer Supreme will get his hands on the Time Stone again, as seen in the Loki premiere titled "Glorious Purpose", arguably offers the most plausible explanation regarding the matter. In the episode, the God of Mischief attempted to escape the Time Variance Authority by searching for the Tesseract that the organization confiscated. He eventually found it through Casey, but as he was handed the cosmic cube, he noticed several iterations of the elemental crystals in his drawer. The trickster grabbed the Time Stone, and throughout the whole outing, even as the Space Stone was taken back, the Asgardian Prince surrenders the green gem. Since Loki is confirmed to connect to Doctor Strange in the Multiverse of Madness, it's not outside the realm of possibility that the trickster will ultimately be the person to hand Strange the Eye of Agamotto for his future endeavors.
Further backing up this claim that the God of Mischief will be instrumental in a Nexus event which left unchecked could branch off into madness leading to another multiversal war" which sounds like a reference to the Sam Raimi MCU film.
As it is, the ongoing Marvel Studios series that is exclusively available on Disney+ is already tackling the idea of the multiverse. Loki has laid the grounds for the concept with the mention of the multiverse war as part of the TVA's history during Miss Minutes' briefing. Initially, WandaVision was expected to do this but ultimately didn’t; instead, it maintained its core arc as a contained project with a character-driven narrative that focused on tackling Wanda's suppressed trauma. In hindsight, the Tom Hiddleston-led series is much better positioned for this function as the show can dissect the idea in a more palatable way before it became a central notion in Doctor Strange in the Multiverse of Madness.
Loki releases new episodes every Wednesday on Disney+.