Right. Keep in mind that you don't need content to match the in-app purchase submissions, so submit in-app purchases in advance. That way, you can make content available on your schedule, not Apple's. Also, the turnaround time for in-app purchases is usually much faster than that of apps—usually one or two days.
Got it! Thanks guys! That's exactly why we're looking into this now. We want to get this part taken care of well before the issue is ready, and since we no longer submit folios for this, I wasn't sure how we go about doing it. But these responses have helped clarify the process. Thanks!