Auto generation is defined on:
info.magnolia.rendering.template.RenderableDefinition.getAutoGeneration()
That mean it can be officially be configured on Pages & Areas & Components.

But it will work only on Areas, because reading and executing the bean is only implemented in:
info.magnolia.templating.elements.AreaElement.tryToCreateAreaNode(Node)

It should be moved/added to the super class shared for all three templating elements:
info.magnolia.templating.elements.AbstractContentTemplatingElement

So it works also for pages and components, as the bean indicates.