The language types function names (used in bootstrap) were reorganized under a consistent pattern/prefix to improve the developer experience.
|Previous name||New name||Rationale|
|drupal_language_initialize()||no change||Expected to change later with WSCCI.|
|drupal_language_types()||language_types_get_default()||Establish a language_types_get_* namespace for list getter functions (there are three of them to unify). Avoid overcrowding the drupal_* namespace.|
|language_initialize()||language_types_initialize()||Initializes language types in fact. Should keep under this 'namespace'.|
|language_types_info()||no change||Returns hook_language_types_info() values altered with hook_language_types_info_alter().|
|language_types_disable()||no change||Disables language types.|
|language_types_set()||no change||Resets the language types cache list (used by all the language_types_get_*() functions).|
In summary all the language_types_*() functions are neatly lined up according to a consistent pattern.