When setting in PreviewGameLaunguage, the package application always adds "culture" to the argument

Whenever packaging project from Launcher with a PreviewGameLanguage set, the culture="preview language" is added to the UE4CommandLine.txt file.
Can avoid this issue by setting "None" in PreviewGameLanguage. However, this seems like bug as the user is presented with an unintended language. It is better that the PreviewLanguage does not affect the applicaton package. 

1. Adding language "ja" in Localization Dashboard.
2. Set the PreviewGameLanguage of EditorPreference to "ja".
3. Adding "ja" in LocalizaitonsToPackage and InternationalizationSupport language in Project Settings.
4. Packaging project from Project Launcher.
5. Launch packaging application.

Result:

Always launch culture "ja".

Expected:

Launch in "en" (Default language or OS language)