Boku no Hero Academia fans worried about the new chapter

This article contains spoilers for the "Boku no Hero Academia" manga. Discretion is advised to the reader.
If you've been browsing social media in the last few hours, you've probably noticed that "Boku no Hero Academia," Izuku Midoriya, and "Deku" are trending terms. This is due to the leaks of Chapter 419 of the popular manga, which have left the community speechless due to the events not unfolding as they expected. Fans expected Izuku Midoriya and Tomura Shigaraki to be shown teaming up against the newly resurrected All For One, but what they received was Shigara's status in question while Deku is defeated.
The chapter revealed the real-life consequences Midoriya suffered after entering Tomura Shigaraki's psyche, seeing the young hero injured and unable to continue fighting. This installment begins with All For One talking to Deku, who is still an armless child, and reproaching him for snatching One For All and Yoichi Shigaraki from him. He then reveals that it was Deku's psychological attacks that allowed All For One to resurface from Shigaraki's consciousness.

Shigaraki is then seen disintegrating into a black void within the imaginary world, watching as All For One tells him that he never made a choice in his life while this is happening. All For One adds that he was the one who led Shigaraki to believe that he had chosen his own path, when in fact All For One was controlling his life from the beginning.
All For One then adds that the only thing his Quirk lacked was an "iron will", beginning his quest to find someone mentally weak whom he could control while All Might grew in power. He eventually met Tomura's father and convinced him to have another child, as his first daughter, Hana, was already too old for All For One to handle as he wanted.
He then shows flashbacks in which All For One takes Tomura home, steals his original Quirk, and gives him a new one. This new Quirk was called Disintegration, experimenting with it to remove the Quirk's ability to rebuild. The Disintegration was transferred to Tenko Shimura/Tomura Shigaraki, with All For One truly controlling his life from the start.

Coming out of the psyche, we can see that Tomura Shigaraki emerges, but he is only a shell, since the mind that dominates his body is that of All For One. He declares that Tomura is dead, that his Quirk, his anger, and his hatred are gone, but that the "vessel" he had prepared for so many years has been ruined. The chapter notes that All For One will resume their plan to conquer the world, and Deku interjects by saying that he won't allow it.
This is where the panel that made this new chapter go viral, with Deku falling to the ground and feeling tremendous pain. It is then revealed that Deku's arms were affected by what happened inside Tomura Shigaraki's psyche, leaving him with mortal wounds that will prevent him from continuing to fight. The situation looks complicated, but then Deku's friends show up to attack All For One and the chapter ends.

Source: Reddit