I'd say I wouldn't expect a confession so quickly, but this story also rockets through basically every other major event they've had so far (tournaments, big matches, most of a year of school), so....
Also yay confession without needlessly drawn out stalling but what the hell was the rest of that? Setting up the big confrontation last chapter with the brother only to have him play it off with a "just joking!" excuse is dumb. If they wanted to continue that drama, have him say nothing after that and just let it eat at Souta that way. This makes it seem like the author did that just to milk the cliffhanger then realize how having them confront the issue now would end it too quickly.
I know people will say (and have said) that this is just slice-of-life and I shouldn't expect an unbroken and consistent narrative, but I also feel like I should expect them not to just clumsily lurch from one item on a "moments to explore" checklist to the next with no care about how they get there. I want to feel like the author put care and attention into crafting their story, and bouncing around with weak justifications and "and then this happened" narration cuts isn't that.
There's a really good story here if things could focus long enough to tell it well.