Well we gotta remember that it will be Joe's debate coaches and handlers deciding on both the questions and the answers and they will base those on vague political science criteria; not paying any attention to what people actually WANT them to talk about. SO, yes; probably.
Trump -- on the other hand -- is likely to bring up anything whatsoever . . . depending on his mood of the moment and the data bingo card his mind lands on in passing. This, of course, makes him essentially unpredictable on timing, if not entirely in regards to content.