The project is a C++ project and some systems are in C++ (ie: Buoyancy and Landscape Modulation), so it is not just blueprints and materials and some blueprints mention components in the C++ code. Completing the steps in the video above with any release, you will have 1st, the project working, and 2nd, a way to transfer what matters to another empty project, so no boats, pier, fish, maps etc
It is important to understand how the sample map works and its elements to get more knowledge about each piece.