I've exchanged into Hawaii Marriotts numerous times and I almost always get the view that was actually deposited with II. However, it's usually one of the worst views in that category....ocean view, but one on a lower floor, mountain view, facing the parking, etc. The Marriotts don't have to give you ocean view, even if that was what was deposited with II. No views are guaranteed on an exchange.
I think you're worrying too much about the view! There's nothing you can do about it, the resort will put you where they want. As an exchanger in Hawaii I take what I get and I'm just happy to be there. I exchange in for far less $$ than the owners pay for MF, so I don't complain about the view I'm given.
I've had some great ocean view units and other times I've had mountain views that faced a parking lot. If you really need to see the ocean, head to the pool or beach and enjoy the view there.
It's a great resort and it's Maui! You'll love it!