Many, probably most, players here and patrons expected Seymour to be Artur 2.0, going by their posts. Something we players who like Seymour always spoke against.
Rome did not throw away anything at all. It becomes clear on the paths where Lena and Seymour have a great relationship and/or are going towards being LIs that the voyage is mainly done for these paths.
As for twists, I would not be surprised if in the game end update on some routes we learned that Seymour is Lena and her (possible) child´s father. If you play the game from the beginning again, you can see hints into this direction several times. It is unclear if Seymour would know or not before. Still, if you are on a Seymour romance path he opens up quite a lot, esp. if you impressed him before. The "sexy librarian" Lena variant, meaning intelligent and hot, is quite able to learn a lot about Seymour.