Relevant Chromium issue ticket is here.
Before people cry, this change was done because people deleted the pre-installed search engine selection and had huge troubles restoring it because there was no option given. So this was done to improve user experience.
They research some solution to provide maybe some buttons or other mechanism for restore deleted providers.
Yeah as shown marked in the screenshot Chrome will get buttons or other options to delete and restore search providers.
This change was made because people deleted search providers and there was no easy or official solution to bring everything back except creating a new profile or mess with some config files.