Rumors have swirled that a divisive MCU Phase 4 movie set up an important Wolverine plot point, but a recent canon update makes that impossible.
A new update to Daredevil season 1-3’s canon in the MCU means that a popular Eternals theory can no longer connect the divisive movie to Wolverine. Charlie Cox’s Matt Murdock/Daredevil has appeared in Spider-Man: No Way Home, She-Hulk season 1, and Echo season 1, and Vincent D’Onofrio’s Wilson Fisk/Kingpin has now shown up in Hawkeye season 1 and Echo. As such, it was easy to assume that Daredevil and the rest of the Defenders Saga was full MCU canon. However, that wasn’t confirmed until recently when the MCU head of streaming removed all doubt.
While the official canonization of the Defenders Saga is exciting for the characters and plotlines it opens up for the modern MCU, it also recontextualized the history of the franchise. One such example is the apparant confirmation of a rare metal back in Daredevil Season 3. This Easter egg is irreconcilable with an Eternals fan theory that tied the movie’s bombastic ending to the X-Men.
Daredevil Season 3’s Ending Teaser Establishes Adamantium In The MCU
At the end of Daredevil season 3, the injured Benjamin Poindexter, aka Bullseye, is seen face down on an operating table. While the sequence may simply seem like a natural follow-up to the grievous wounds Poindexter suffered in the three-way brawl between himself, Kingpin, and Daredevil, comic readers will recognize some big implications from his procedure.
In Marvel Comics, Bullseye is more durable than average people because his skeleton is partially coated in Marvel’s ultra-strong, fictitious meta, Adamantium. The surgeons working on his spine and the odd-but-present classic Bullseye logo that appears in Benjamin’s eyes tease a comic-accurate version of the character, but it’s the doctor who lends credibility to this theory. It’s none other than Dr. Oyama, who, in Marvel Comics, is a master of Adamantium and created the tech that creates Wolverine’s unique skeleton.
Bullseye’s Adamantium Upgrade Dispels An Eternals Theory

Given Daredevil season 3 takes place earlier in the MCU timeline than Eternals, Poindexer’s Adamantium upgrade seems to dismiss the idea that the metal is of Celestial origin. Instead, it seems more likely that, like in Marvel Comics, it’s simply a difficult to use alloy created by human scientists.
How Else Tiamut’s Body Could Be Used In The MCU’s Future

Even if Eternals‘ Tiamut isn’t used to explain the MCU’s Adamantium, there’s another popular theory that seems possible. In the pages of Marvel Comics, Jason Aaron’s Avengers use a the body of a long-dead Celestial to form Avengers Mountain, a base in the arctic. Given the Avengers’ campus was destroyed in Avengers: Endgame in the Battle for Earth with Thanos, the group may need to relocate. Tiamut, in the middle of the Indian Ocean, makes sense.
Given the Avengers’ tenuous history with the US government, which will likely get worse in Captain America: Brave New World, the team may want to go somewhere without political restrictions. This would distance them from now-president (and possible Red Hulk) Thunderbolt Ross and offer an easy-to-defend location away from potential civilian casualties should another battle erupt. Time will tell, but it seems that Daredevil means this specific Eternals theory isn’t meant to be.