At the moment, to facilitate adoption of a feature we implemented to improve manipulation of sprints throughout JIRA's UI, the Sprint field will be added to all Create/View/Edit screens (the screens used by the project) each time a new project is created and enabled for Agile. This is actually an improvement based on the highly voted ticket, as mentioned in GHS-10767.

However, in the case where the screens are shared accross multiple projects, this automation (sprint will gets automatically re-added into screens) will affect other projects, as they share the same screens. It would be better to have the options for the Sprint field to NOT be automatically re-added whenever a new project is created and enabled for Agile.