“Oh.” Oh as in oh thank god it's not something serious, because I have to tell you something usually precedes a comment like I'm about to go to jail or I have cancer or my father just died or something.
Honestly, though, Wolfgang has no context for any of this, they have no idea what half of that means. (What's a BBDO?) They're not sure what the level of enthusiasm they're supposed to display is. At least it's nice to see him excited and smiling and not looking like he's going to throw up all over their nice clean floor. “Well, congratulations. Is that, um... I... I'm sorry, I don't really know what this means.”