(this isnt about the last ask I answered! its another)
its clear deku wants katsuki still in his life and wants to involve him in his "new passion", we dont need a scene of him running towards him bc they already are part of their lives -he is just involving him even more in his-. While the scene looks romantic, its actually quite sad for anyone who is actually reading it and enjoys deku and ochako as friends/lovers -it confirms they never got closer during nor after school beyond what we already saw, and they just lost contact. Instead of being comfortable with each other like they used to, now its a little weird, and Izuku even gives the opportunity to reject his offer of talking more from now on. He is not out there asking katsuki if he wants to be a special lecturer, he should be
When Ochako is thinking about him before he meets her, shes reflecting on their dynamic and why they just arent as close -they had different paths to go and respected each other, laughed when they could, and she shouldn't feel bad about not talking during the reunion bc they already see each other more. She thinks its already a "luxury" that they were able to talk normally before. She put those feelings away, however she wants to talk more to him still. We get also a flashback to her confessing that feeling to Himiko. And then he appears and says that he also wants to talk to her more!
In the end it doesnt read as him confessing romantic feelings towards her, but Ochako having the opportunity to get closer to him instead of just keep living without doing what she wants to do. Tbh, now that im re reading that chapter, it reads a lot like Izuku towards Katsuki during that scene where he says he is too blessed, with his perspective that anything is good enough when it comes to him.
Could this be a set up to make the one shot revolve around her confessing romantic feelings? Sure it could, but its wild to say 431 confirmed a relationship between them or solidified it -they see each other more but arent close, so its awkward. Himiko's advice to Ochako is living more like she wants to -so I prefer to see it as her being told to also talk to the ppl she wants in her life-.
Fun fact, according to pikahlua her agreeing with him can also be translated as "we get along!", which could be so cute for an interpretation about them wanting to reconnect their friendship, as her saying something like "ofc we can talk more, we'll always get along!".
Its like Ochako and Izuku arent able to even think about rescheduling or involve the other actively in their life until now that Katsuki told him to start showing others how they are special too, instead of just treating everyone the exact same, even tho their jobs are pretty similar and would work together pretty easily as opposed to Katsuki and Izuku's jobs. And in the end, Katsuki didnt need an extra moment of attention bc he has always had that special treatment -if he didnt, AFO wouldnt have targeted him in the first place-.