No, you have to drop to Gold first. BUT as a Plat who gets 74 nights by the end of this year, in all likelihood Marriott will keep you as Plat for the next year. This has happened to me twice in the last 6 years. One year I only had 35 nights, and last year I only had 61. Now I have been Plat for 12 of the last 13 years, and as primarily a leisure traveler I also book the majority my hotels 11 months out and have the track record of completing those stays, so perhaps longevity and pending future business have a bearing on that decision by Marriott.

If you want the official answer see post #23.