No. You only need to supply enough to entice readers to pre-order. Each writer is different in regards to how and when they choose to release chapters. Some base it on pre-orders, others on a schedule. I have not released anything in quite some time because I’m doing some considerable rework and I want to present my best at once.
Unfortunately, there is no way to hide content for only those who pre-order, but I hope they release a feature for this in the future.
