Arata's goal in the story is to show the change Mei has gone through thanks to Yuzu and to cement her role as the new chairwoman of Aihara
What about Mei's administrative role at the Aihara school has needed to be "cemented"? How have the nuances of that role ever been a central issue in this story, except for Mei spending exponentially more time and energy on that job than on her relationship with Yuzu?
maybe i'm wrong but i think they mean cement as in showing the actual, practical work she's doing rather than just "studying a lot and doing overtime at the student council".
Because aside from the romance itself, being the new chairwoman always was a central issue of the story since it's Mei's #1 driving force, informing nearly every decision she makes throughout the series.
So I think it makes sense Saburouta would want to expand on that aspect.