In the timeline view you can easily drag an item, which is both handy as very dangerous !
One can very easily accidentally drag an item to a different date, while intending to just navigate through the timeline.
This risk increases with the number of users.
Of course, you can change column permissions (restrict edit of period column), but there can easily be cases were all users must all be able to change dates, but just NOT from the timeline view, as the risk of accidentally doing that is significant.
I suggest an option to enable/disable dragging of dates in timeline view to easily control this.