There are some mentions of Sevestre in a sidequest or two, such as "A Literary Delivery" where he winds up ordering a book about Ishgardian Astrology because of how Leveva blackmailed him, leading him to study up on it to see how Sharlayan astrology is being "perverted".
You can also catch a glimpse of him in cutscenes when the Forum is gathered as a cameo since he's a member. Predictably, he votes against our heroes.Originally Posted by A Literary Delivery
However, his concerns are largely petty and overshadowed by the Final Days. And Sharlayan's opening of its borders following the end of its great work basically renders the Bibliothec's whole platform moot. It could be interesting politically to see how he and others like him would respond to this, but ultimately it's not the Warrior of Light's problem anymore and we're unlikely to explore it.
That said, I would like to dwarven deck him at some point.