Let’s start with one easy detail: fire. As the original theory pointed out, Anna is often coupled with the elemental fire power attribute due to her warm-weather birthday. The obvious problem here? There already is a fired-up spirit in the “Frozen” universe. Remember that harmless-looking little salamander from the sequel? Yeah, that’s Bruni. The undersized character already fills the role of the elemental spirit of fire in his world. Having Anna also get fire powers would only be redundant now that Bruni’s in the picture.
The other obvious issue with Anna getting powers was pointed out in the original theory, as well, when u/LockAndKey989 elaborated, “Elsa and Anna are supposed to be the bridge between magical and human worlds. That’s why Elsa has powers and lives in the forest while Anna becomes queen of Arendelle.” This is pointed out by Elsa as well, and it’s the state of things when “Frozen II” ends. Anna is the new queen of her very human people. At this point, it’s clear that her humanity is an important part of her fitting leadership. In contrast, Elsa’s magical nature made her feel out of place on the throne.
In a highly upvoted comment beneath the primary post, Redditor u/Falathrin added, “I also feel it wouldn’t be as impactful since we already have Elsa with magic powers.” Falathrin compares it to Pocahontas, adding that in that case the character getting powers would be unique. With Anna, it would just be more of the same.
All of this doesn’t even touch on the sheer logistical nightmare that having fire powers in a very wooden human settlement could create. If Anna gets fire powers, does she burn down Arendelle as a result?