There are already pre-defined labels for the e-mail in different languages (e.g. default.report.emailTextNoEmail) but they are currently non-functional :-(

Configuring the Feedback Tool for the New Primo UI
https://knowledge.exlibrisgroup.com/Primo/Product_Documentation/Primo/New_Primo_User_Interface/Additional_Features_for_the_New_UI/Configuring_the_Feedback_Tool_for_the_New_Primo_UI
"Note: Only the en_US descriptions are supported for email labels, and no translations are provided if configured in the table."

According to Production Management, implementation is not planned for the time being and we should raise an idea.
So, please vote for this idea ;-)