Warning! Spoilers ahead for My Hero Academia chapter 338!
Shoto Aizawa's plan for class 1-A's upcoming mission that My Hero Academia has yet to disclose is destined to fail since All For One might already know that Yuga Aoyama and his family are compromised. Proving this theory are key comments made during Yuga's questioning and how the assassin Lady Nagant almost died many chapters ago.
During Yuga's questioning, Deku and his classmates (except for Katsuki Bakugo) hoped that Yuga could redeem himself by somehow helping them defeat All For One as a double agent. Police force member Sansa Tamakawa, however, ostensibly dashed those hopes when he reminded everyone that the Aoyama family had already told them that All For One knows when he's being lied to. Following those comments, Aizawa orders plugging Yuga and his family's ears before divulging his plan in chapter 338. It's important that Aizawa tells his plan right after Sansa's reminder.
The fact that Aizawa compromises the Aoyama family's hearing during this pivotal moment proves the likelihood that his plan still involves Yuga the traitor telling a lie to All For One. Aizawa undoubtedly believes that if All For One knows when he's being lied to then the obvious answer is for Yuga to not know that he's telling a lie. That's why Aizawa had Yuga's ears covered because he most likely told the lie that Yuga will tell All For One. This way, Yuga won't know what he's saying is a lie and therefore All For One won't be able to tell that he's being lied to. But therein lies a possible fatal flaw in Aizawa's plan. All For One might have the ability to detect untruthfulness, but not because he's a mind reader. It could be because he somehow possesses the ability to hear what Yuga hears.
All For One proved this might be the case during the mission he gave Lady Nagant to collect Deku. The moment she betrayed All For One, a bomb that he most likely implanted in her using the self-destruction quirk immediately went off. In other words, the villain knew when Deku convinced Lady Nagant to come back to hero society and atone for her sins. How could he have known to detonate the bomb at that exact moment? There's the possibility that he set a time to detonate the bomb since All For One later revealed that he expected she would betray him. But that still doesn't explain why the bomb went off right at the moment of her betrayal. Aizawa and his colleagues obviously don't believe that All For One can tap into Yuga's hearing because All Might said that All For One set the bomb to detonate inside of Lady Nagant, implying that the quirk exploded on its own.
But how can My Hero Academia's upcoming mission be compromised if Aizawa plugged Yuga and his family's ears before he shared his plan? If All For One can tap into their hearing, then he didn't hear the plan either. It's compromised because their ears weren't covered when not only Deku but the vast majority of class 1-A decided to help Yuga and when Aizawa said that he wouldn't expel him. If All For One heard those comments, then he knows that his spy is no longer useful to him and that anything Yuga does from this moment on will be in service of My Hero Academia's hero society.