Implement hook_field_create_instance(), hook_field_delete_instance() and hook_field_attach_rename_bundle() When creating a new field type (e.g. address or dimension), I am looking for the Drupal 8 equivalent of hook_field_create_instance() and hook_field_delete_instance() that are available in Drupal 7.
The same goes for hook_field_attach_rename_bundle().

The hook_field_create_instance() could be used e.g. for defining default values on existing entities. Let's say define the new field default value on existing Node instances after attaching (= creating a field instance) to a Content Type.

After digging around on the parent classes and interfaces of the classes that are involved in the definition of a new field type (FieldFormatter, FieldType, FieldWidget namespaces) + Field Types API, I found the PluginManagerBase::createInstance (and thus FieldTypePluginManager::createInstance) but didn't found a way to define custom code for these operations.
These two drupal resources should get you there: 


https://www.drupal.org/node/2054619
https://www.drupal.org/node/2012896


As an aside, here is how I found the changes: Drupal Changes