Is it possible to make souffles that rise without beating egg whites?
TL:DR answer - not really. The beaten egg whites are an integral component of the souffle, forming both the rising action of the mixture (by capturing air within the protein network of the eggs) and and the structure. The recipe you linked to is more of a cake than a souffle, even using the creaming method commonly seen in cake production. 

While other ingredients can capture air as well (such as the gluten formation from flour in a cake or bread), they change the nature of this dish so much that it's no longer recognizable as a souffle. 

Adding baking soda unfortunately won't help in this particular instance as the rise caused by this is due to the carbon dioxide gas released. The souffles have that part covered with the air bubbles released during baking - what they need is the structure to trap them in. 

I hope that helped to clarify!