score:6
Not at all.
The decision to create a new capital at what we now know as Washington D.C. had been taken in 1790, three years before the yellow fever in Philadelphia. There were a couple reasons why the new republic wanted to move the capital from Philadelphia.
The first reason was that the republic wanted a capital closer to the center of the country on what was then a north-south axis (basically the 13 colonies). That meant further south.
The second reason was that they wanted a capital district (of Columbia) that was independent of any state. That ruled out existing cities. Instead, the founding fathers found a piece of land further south, on the border of Maryland and Virginia, that was considered "expendable" by the two states, on which to build a new capital from scratch.
The southerly move was a sop to the Southern states, who then agreed to allow the more heavily indebted northern states to transfer their Revolutionary War debts to the new Federal government. Given that such a deal had been "brokered" by Hamilton and Madison, it was a point of "no return" that did not allow for reconsideration of Philadelphia, the original capital.
It took until 1800 to actually build the capital, but that's a different story. The decision had been taken ten years earlier. A yellow fever epidemic in what was then three years in the future had nothing to do with the decision.