Cheesecake in or next to waterbath
The purpose of the water is to cook the custard slowly- essentially poaching it. It takes out some insurance against it overheating and breaking.

Suspending the cheesecake over the water would not have the same effect- steam can get hotter than the curdling temperature of eggs. It would be a thermal mass that might even out some temperature variation in your oven and it would keep things humid. If your oven is working well these effects aren't needed.

Plenty of cheesecake recipes don't take out the water-bath-insurance. My opinion is that suspending the cake above the pan would not be helpful.