I didn't save the sheet of paper they gave us, but last year in June, the NV location had everything spelled out (in writing) of what you'd get if you attended the presentation and the "benefit" was that you'd get those items on Day 1 (ie, date of arrival) even if your presentation was later in the week. I honestly do not recall there being an exchange resort fee credit on that sheet, but we were in via SFX ($75 back then). AFAIK, the Interval pre-pay resort fee credit is something direct through Vidanta that they send you (email) or call you around 4 weeks prior to arrival. If you get the email it's worded like your reservation will be cancelled if you don't pre-pay.
Just keep in mind that the pre-pay is NON-REFUNDABLE. So either increase your travel insurance coverage (if needed) to compensate, or keep that in mind.