I don't think they've brought back the rib entree to the menu at Docking Bay 7 yet, but you could keep an eye out for that. There's a brisket mac and cheese somewhere (possibly Smokejumpers at DCA?), and, as brentm77 mentioned, the Bengal BBQ (which is skewers, not really BBQ).
If ribs are really, really important, I believe there's a Tony Roma's across the street on Harbor (walking distance), people have varying opinions on their food.
But honestly, I'd scan the DTD restaurant menus for better overall food options. Maybe try Ralph Brennan's Jazz Kitchen and see if they have something for your dad?
We are planning some sit-down meals at DtD to escape the parks mid-day.