Neither Louis the Grand Dauphin or his son Louis, Duke of Burgundy die of smallpox in 1711/1712 (although Burgundy's wife and eldest son still die on schedule).
The Grand Dauphin succeeds his father in 1715 and becomes King Louis XV, ruling until his death in 1726.
Burgundy succeeds his father in 1726 as King Louis XVI and rules until his death in 1748.
In this timeline our Louis XV becomes King of France as Louis XVII in 1748 aged 38. What are the consequences of two extra Kings of France, and our Louis XV becoming King as an adult instead of as a child?