It appears very likely that the omitted Elden Ring material about Miquella will show up in the upcoming Shadow of the Erdtree DLC.
While FromSoftware has made the Shadow of the Erdtree DLC for Elden Ring's game official, it remains a mystery. Fans may have to wait a while, given that Elden Ring's marketing was essentially nonexistent until a few months before its release. There are numerous theories out there right now regarding it, from the timing and condition of the Erdtree to the enigmatic tree that is consuming it and the figure on Torrent. The latter is frequently assumed to be Miquella, and for good reason.
Elden Ring doesn't feature any physical depictions of Miquella, but the game frequently refers to him as an incredibly strong Empyrean who is closer to a God than anything else. Miquella, who is eternally young, develops the Haligtree to treat both himself and his sister before Mohg, the Lord of Blood, steals his cocoon. Not only does Miquella resemble the person in the picture, but since he invented unalloyed gold, the gold that is bleeding from the Erdtree may also be connected to him. Others contend that the roots are connected to Godwyn's Deathroot and that the dying Erdtree may be engaged in a struggle for dominance. Again, this is only speculation because nothing has been confirmed, but if Miquella is indeed involved, cut content regarding him may make an appearance.
The term "cut content" can occasionally be viewed negatively by fans who believe that it refers to content that was removed from the original game in order to be repackaged and sold. This is not the situation. Elden Ring is already quite large, so it makes perfect sense to cut some content to ensure that fans wouldn't be overwhelmed. The Colosseums were actually uncovered as "cut content" from the game that was later added without charge. Because Miquella is absent from the base game, it makes perfect sense to cut content about him. In light of this, it's possible that some of the content that was cut could lead to this DLC.
An item called Dream Mist (or Dream Brew), which is among the cut references that imply Miquella would use St. Trina as a secondary name, could very well be crucial in the upcoming DLC. According to information available at the time, it would entail a globe-trotting search for different ingredients connected to a monk by the name of Jiko. Then, supposedly, this item would put NPCs to sleep, letting players enter their dream. The fact that players must enter Fia's dream to battle Lichdragon Fortissax proves that dreams function differently in Elden Ring, so this does not imply that the entire DLC is a dream. Indeed, it seems dreams are a gateway to another world of sorts in Elden Ring.
This is significant for two reasons: first, it suggests that Miquella has entered the Haligtree and is now imprisoned in some kind of dream-state inside his Cocoon. He might have been able to observe Elden Ring's world, but not interfere as a result. (frighteningly meaning he knows players killed his sister, Malenia). In any case, this item might enable players to enter Miquella's dream, perhaps rousing him from his sleep or something similar. The second is that St. Trina's Crystal Ball, a cut item, still exists and enables players to "steal" dreams from other NPCs.