Yeah once you see nitrates start the weekly water changes, the initial cycle is complete no further growth of bacteria is a achieved, they simply convert the existing ammonia and nitrite into nitrate. At that point water changes speed the remaining cycle so a fish or coral can be added by ridding the water of the remaining nitrate and all nitrite, ammonia is gone.
My last tank i cycled i had a fish and softies in the tank in less than 2 weeks and no problems. Just have to take it slow like everything else.
Does this mean your tank will cycle in 2 weeks? Absolutely not, it just explains how it will not prolong the cycle compared to no water changes. Hope thats understandable.