Oh. Well, still Boromir before the arrows. At that point he’s basically written out of the story anyway.
I can find him work petitioning the Tolkien estate to include firearms in their final battle, which they will likely refuse because they are dicks. I guess he could go on celebrity panel shows, but I don’t think he’d be that funny.
Pulling him out of the book really might do more harm than good. He died with courage. Now he just mysteriously vanished when he was needed the most. Probably the King Steward of Rohan would be suspicious on his son’s disappearance, and would reject any plea for aid fr the Fellowship. Might doom the story.