While creating a multi language translation project I have observed that if pages are already created in target language and we select page from source language then AEM creates a launch copy of page and display a path like this.
for example :- I have created a translation project for language FR and DE. Source language is EN. when i select page "donate-to-our-mission" from en language then it show below path in translation project
When the destination language copy (page, asset etc) already exists, "AEM treats this situation as an update translation. A launch is created and a copy of the page is added to the launch, and included in the project." This functionality is same for single language as well as multi language projects. For details please refer to .