Again, with all the factors considered, he's at or below a 5% chance of dying from the Kung Flu. Long-term complications are possible, even somewhat likely.
So, is it realistic to be worried about the President's confidence right now, when the illness is still early? Sure. 5% is a higher risk than the typical chances of other causes of fatality for the President, such as assasination, plane/car crash, and stupid luck. A meteor miraculously splattering Trump is a non-zero probability.
So I guess it's depends on how you think of applied probability. Would you trust a plane with a 5% chance of crashing? I wouldn't, myself. Would you invest all your money in a company with a 95% chance of making massive returns? I would, myself.