I don't think this is rushed in the sense that we've had 300+ chapters of relationship building and we all know the girls like him, but it is jarring in the sense that we don't see any of the girls plan for this at all, it just kinda happens.
It might have read better if there was a build up to this moment in the past couple chapters. I understand the episodic nature of this manga usually makes that impossible but I figured, at least for the big confession moment, the author would work on a more continuous arc.
Which is also what makes me think this might still be a bait and switch. Daisuke is dense as a brick after all, receiving genuine valentine's chocolate might not be enough to get through his thick skull. We could just get a punchline on white day.