Q. Does data management and sharing mean that I must make my data available immediately, even before publication?
Not necessarily. The expectation is that all data will be made available after a reasonable length of time ( sometimes called an "embargo period"). However, what constitutes a reasonable length of time will be determined by the community of interest or the needs of the project, and may depend up on funder requirements. When you deposit your data into a data repository, you can review your options for setting access controls and embargo periods.