Translate «The term '@term' will be added.»

This is working on 2.0.x-dev without any patches.
The strings are configured on form display, so you can simply create config for specific language and specify translated values for not_found_message and no_empty_message.

For example, you have Ukrainian as second language on site and want to translate this values for field_tags on article default form display, then you need to put new file core.entity_form_display.node.article.default.yml into [your_config_sync_folder]/language/uk/
wtih something like that:

content:
  field_tags:
    settings:
      not_found_message: 'Новий термін ''@term'' буде додано'
      no_empty_message: 'Немає результатів. Будь ласка введіть початок.'

After config import your strings will be translated when page displayed in Ukrainian.

Hi @rajab-natshah
this can be simply "Closed (works as designed)" as it is possible to translate all those texts through config translation