No way of knowing.
You will lose some beneficial bacteria as some will be living on your substrate and decorations. If you are careful with your filter and dont let it dry out you should be able to retain most of that. Whether the amount you lose causes a noticable crash with your cycle, no way of knowing. Its likely you will see some spike in ammonia and/ or nitrite. If your filter is oversized and there is enough media to support an increased amount of bacteria then the spike is likely to be short lived and your cycle will catch up quite quickly. If your filter and amount of filter media is already at capacity and you are relying on beneficial bacteria finding its way back into the tank onto whatever new aquascaping you will be doing, then it will take longer for your cycle to catch up. Squeezing out an established sponge into the water could get some bacteria onto your new aquascape a little quicker.