AEM Launch based Translation Jobs are deleting all the child pages under a language copy root page after receiving content from an external translation service

We are facing with a rather unique issue where after translation is completed and content comes back to AEM, the Home Page gets updated, but the rest of content tree below Home Page is deleted. We are using smartling as a translation provider. Even though we don't submit the entire tree with in the translation job, the launch promoting the content from Smartling to AEM is assuming so and since the content is not available, it is wiping out the existing pages. 

Upon log inspection, we see that the Translation Job Service is responsible for the pages to be deleted as there is an audit event recorded highlighting the page deleting

Has any experienced this before??

Is there a launch promotion setting in AEM that can be overridden, where we don't delete the existing page if the launch which does the promotion does not have the content ?