Geometry with no series still renders, with labels, hover and tooltips. There is no "empty state" branch anywhere in the drawing path: when no series is configured the map draws a basemap pseudo-series instead, so hit testing, labelling and accessibility all work the same way they do with data. A basemap is also drawn underneath point-only series, because bubbles floating in the void with no coastline is not a map.
Labels are laid out in screen space every frame and dropped when they would overlap, largest
feature and largest value first, so the labels that survive a crowded view are the
informative ones. minFeatureArea skips labels for shapes too small to carry one.
Zoom in: more labels appear as the collisions resolve.
dataLabels: { enabled: true, collision: 'hide', minFeatureArea: 900 }