Your plant is obviously healthy and growing vigorously, and the new spike looks normal to me. If the plant wasn't strong enough to support the new growth it wouldn't try. There is very little truth to the warnings that healthy plants can weaken or kill themselves by blooming too much or by carrying seed pods. It really only applies to young seedlings and plants that are already stressed. Yours is neither. The cool nights may have triggered the new spike, but that is perfectly normal.