Bakugou has always been very observant and able to discern people's weaknesses extremely quickly - in pretty much every fight we've ever seen him in with the only possible exception being that exercise versus Deku where he underestimated him. Blackmist/Kurogiri he went for the plates to shut him down, he figured out how to counter Tokoyami 's quirk, immediately went for Todoroki's fire-side knowing that he's hesitant to use it, etc. He's been nothing but heads up so I'm kind of surprised how many people had written him off as an idiot - I guess from his first fight with Deku, or maybe the typical "stupid bully" trope?
Anyway… given Bakugou's history of being able to quickly discern weakness, I have a feeling that he's gonna figure out that something is off with All Might during their fight.
Y'know, this post has made me wonder. Does anyone think Bakugo might or might come to suspect the truth behind the fight with Stain? He knows what Deku, Todoroki, and Ida can do. Wouldn't shock me if he thinks that the three of them combined might be able to do it.