For a movie that we won't see for more than two years, we know an awful lot more about Thor: Love and Thunder than we do most of the MCU's upcoming projects. The fact that Natalie Portman will return to the MCU, and also become The Mighty Thor, was revealed on the San Diego Comic-Con stage, so the big question of the new film is not what will happen, but how will it all happen.
Has Jane Foster always been worthy of lifting Mjolnir? If not, what events will transpire that will result in her becoming worthy? Of course, these questions are only important if Jane Foster needs to be worthy in the first place, and a new interesting theory making the rounds online suggests there's no need for all that.
A theory on Reddit from user justhadto suggests that, since Odin is dead, the enchantment he placed on Mjolnir would be gone, and thus there is no longer any requirement of worthiness attached to the hammer.
In Thor: Ragnarok, it's the death of Odin that frees Hela from the prison she's been banished to. Odin's power has been keeping her prisoner, and so with him gone, she is freed. The idea behind this theory is that the same would be true with Mjolnir. Any other enchantments that Odin had created in life are now gone.
In the first Thor movie, we see Odin enchant the hammer with the whole "Whosoever holds this hammer, if he be worthy, shall possess the power of Thor" thing. This would seem to indicate that prior to this happening, anybody could have lifted the hammer. Also, this explains why Hela was not only able to hold Mjolnir, but destroy it. It was no longer under the enchantment because Odin had just died.
And then, of course, there's the fact that Mjolnir was destroyed, and while we expect it will be coming back in some way so that Natalie Portman can smash dudes in the face with it, it might be a new version of the hammer that's been reforged or otherwise recreated. If it's not technically the same hammer that Odin enchanted, then the deal's off.
While this theory does hold water, it's certainly less than exciting. Part of the joy of seeing Captain America life Mjolnir in Avengers: Endgame was everything that represented, that he was worthy of the weapon. If Jane Foster is able to life Mjolnir because anybody can, it won't be nearly as cool.
This really is just a theory, as writer and director Taika Waititi has intimated that the script for Thor: Love and Thunder has really only just gotten underway, so it's possible nobody knows just how all this will work quite yet.
We'll find out when Thor: Love and Thunder hits screens in November of 2021.