This post contains spoilers from chapter 269 of My Hero Academia. You have been warned.
Shigaraki has finally been released from his capsule, but something is wrong! Shigaraki is not breathing and his heart has stopped. It is revealed that Shigaraki is not dead, but in a state of suspended animation like a bear in hibernation. The rest of the superheroes who participated in the hospital raid have joined the fight and have overwhelmed the other High-End Nomu. At first, it looks like it is a final total defeat for Shigaraki, but this seems way too easy for the superheroes. Something’s not right!
At the end of the chapter, we got a glimpse of All For One while he is in prison, seemingly smiling. This could mean that All For One has an ace up his sleeve to somehow awaken Shigaraki. The security system of Tartarus Prison is specifically designed to shoot inmates if they so much as think about using their powers. However, they have never dealt with someone of All For One’s capabilities. For all we know, All For One may have some way to hide his thought patterns from the security system or have some form of technopathy that tricks the security system. Another possibility is that All For One may sacrifice himself to awaken Shigaraki. Due to being weaken and a broken shadow of his former self, All For One may sacrifice himself for his legacy in Shigaraki by using some kind of psychic power that awakens Shigaraki. In doing so, All For One would be gunned down, thus paving the way for Shigaraki to inherit his throne as king of the underworld.
If Shigaraki somehow awakens with all those superheroes present, I can imagine seeing something similar to when All For One first reveals himself in My Hero Academia. In that scene, All For One effortlessly defeated four superheroes and destroyed the surrounding area with one blow. I think we will see something similar when Shigaraki awakens, but on a much larger scale due to the number of superheroes present. I am imagining something similar to when Madara Uchiha single-handedly mopped the floor with the entire Ninja Alliance in Naruto.
Overall, since Tomura Shigaraki is the main supervillain of the story alongside All For One, there is no way he could be dead or be defeated this soon. All the foreshadowing and story arcs have been leading us to something big and I think it is something bigger than the war arc so far.