Overall plot wise this was an entirely unneeded chapter and the case could be made the set up makes no sense (How the hell would Katou not know how strong Baki is, all of his matches and deeds like the father/ son fight are very public knowledge?) but it is a bit of nice characterization for Baki.
As soon as the last chapter came out people were making memes about Katou being reduced to a puddle on the floor/ turned into another Retsu nugget, but that's just not the type of figher Baki is. He's like some sort of in between of Yuchiro and Yujiro, wherein he's not going to roll over and pretend to be weak because he doesn't care but he's also not going to murder/ other activities you because you challenged him. He's just going to gently let you know you ain't shit