The final plague struck down all the first-born males in Egypt. Paro was not struck down this way, so does that mean he had an older brother? If so, what happened to him that Paro, not the older brother, got the throne? (Google led me to speculation that Paro was Thutmose I, but I don't see anything there about siblings and, anyway, we don't know if he's the right Paro.)
Or wouldn't Paro have been struck down anyway, because God had other plans for him?