Technically you will need some sort of ammonia spike to feed the bacteria. And since it seems like you have time on your side, there’s no reason not to.
As scottb said, keep an eye on the phosphates during that time. Make sure they don’t bottom out, and if they do, dose over a couple weeks till they come up to a normal range. Once everything ammonia and nitrite come back to zero you’re technically cycled and can swap everything then. That being said, I used fritz turbo start and everything stalled about day 8. I went ahead and swapped my fish over anyways, and everything has been perfectly fine. My ammonia and nitrite didn’t zero until I put fish in, and after a day or so they dropped off altogether.