Change record status: 
Introduced in branch: 
2.0.x
Introduced in version: 
2.0.0-alpha1
Description: 

The abstract base class \Drupal\reference_table_formatter\FormatterBase has been removed, with its existing functionality merged into \Drupal\reference_table_formatter\Plugin\Field\FieldFormatter\EntityReferenceTableFormatter.

Impacts: 
Module developers