Not necessarily. Award availability for any MVCI property (Marriott's timeshare arm) is different than for a 'hotel'. Marriott doesn't "own" the room nights at a timeshare, the owners do. If an owner wants to use their week(s) or if they want to rent it out, or if they want to trade it in for a week somewhere else, Marriott has no real say in that and still doesn't have access to the room.

The primary way Marriott will be able to offer award room nights is when an owner trades in their week for Marriott points. The problem with that is some MVCI properties are more expensive to own then other properties (i.e. Hawaii for example). Owners of those more expensive properties are much less likely to offer up their week(s) for points. They will want to use, trade or rent their week instead. Some locations where costs are much lower and have more timeshares to choose from (i.e. Orlando is a good example), you might be able to find award inventory more plentiful.

With all that said, I have personally used points for stays at the Kauai Beach Club, Waiohai and Ko Olina, all in Hawaii. So they do show up. I stayed earlier this year for a week at the Aruba Ocean Club (the Surf Club also had availability as well, but I preferred the Ocean Club.) I've stayed at the St. Kitts Beach Club, Legends Edge (in Panama City Beach, FL), the BeachPlace Towers (Ft. Lauderdale) and have stayed at the Imperial Palms in Orlando a few times. I've always liked using points at MVCI properties and will usually get a 2-bedroom unit (though the Imperial Palms is an all 3 bedroom property).

So it is possible. Some places it will be easier. Others you might have to wait years to find a week.