I don't believe that Yuzu fully understood the situation, she's just so earnest and true to her desire to make people around her happy and so, she assumed (correctly) Mei's motivations this time.
Matsuri on the other was really fleshed out as a character and as expected, her actions were to catalyst for development between the sisters. Mei has finally starting to come out from her shell and taking the initiative instead of reacting to the situations. Without a doubt, a great chapter and I'm really happy at how Citrus is handling the drama (in stark contrast to The Feelings we have to endure for example)
That being said, it was a poor choice to resolve Mei's date offscreen. Probably was to space constraints but it hurt the narrative a little.