The Third Years Graduating / Tōtsuki 10

We all who follow the manga know that Souma and the rest are close to graduating from being freshmen. However this also means that the Seniors will graduate. We do not know many of the seniors, so it might not matter as much, however what does matter is the fact that most of the Tōtsuki 10 are Seniors.

Questions

What will happen here, does this mean that Souma will not be able to challenge Rindou and the others? Will he not be able to have a rematch against the current 1st seat? Perhaps this favors the theory that Erina will be Souma's final opponent at Tōtsuki. Does this mean that we might see a manga that proceeds after even Souma graduates?

Share some of your thoughts!