They aren't completely empty; the localization system is no longer tied to the packager, so now any and all projects can take advantage of the system - what you downloaded was the results of the packager run, before the localization processing was done. There is a ticket in to hide the files even from the project owner until the processing is completely finished, since this seems to be a recurring issue.
From your deDE.lua file:
L["Accept Whispers"] = "Flüsternachrichten akzeptieren" L["accept_whispers_desc"] = "Ermöglicht es Spielern, ihre(n) momentanen Gegenstand/-stände zu dir zu flüstern, um dem Abstimmungsfenster hinzugefügt zu werden."
Thanks for your response. I double checked through the Curse client, and they are indeed injected correctly - however it's still not included when I download it manually from the files page on CurseForge.