If you have a chain of dependent tasks, you can mass reschedule them on the Gantt chart. Gaps between tasks are preserved when you reschedule tasks in this way.
When you shift one task in the dependency other tasks will follow.
You can add milestone tasks to the dependency chains. However, they don't shift when the tasks in the dependency chain get rescheduled. To move it you have to shift the dependency as a whole.
Create a chain of tasks joined by dependencies.
Press and hold Shift on your keyboard.
Click a task that's part of a dependency chain on the Gantt chart.
Drag and drop the task to the appropriate date.
All active tasks in the chain (including milestones) are moved.