My reasoning is that the coffee will cool in a curve having high rate of temperature change at first, and slower later in a long tail until it reaches room temp. Adding the cream will "remove" a fixed amount of "heat units". The heat of the cup can be graphed as heat/time and it will look like exponential decay.
If you remove those units at the start, you've reduced the starting temp a bit, but you haven't much changed the long tail of the cooling. You essentially just started the coffee at a slightly cooler temperature, but this doesn't affect the curve much. Or to think of it another way, the change in temperature at the start corresponds to a small amount of X axis (time) on the curve.
If you add the cream later, the temperature reduction corresponds to a larger amount of time on the curve. This means the temperature will be lower than the above.
So to my intuition, cream first should yield hotter coffee
If you remove those units at the start, you've reduced the starting temp a bit, but you haven't much changed the long tail of the cooling. You essentially just started the coffee at a slightly cooler temperature, but this doesn't affect the curve much. Or to think of it another way, the change in temperature at the start corresponds to a small amount of X axis (time) on the curve.
If you add the cream later, the temperature reduction corresponds to a larger amount of time on the curve. This means the temperature will be lower than the above.
So to my intuition, cream first should yield hotter coffee