With German releases the language of the title used for the home entertainment release will usually reflect the title used for the film's cinema release. If the title was translated into German for the cinema then the title of the home entertainment release will also be in German. Conversely, if the film was released with its original English title then the title of the home entertainment release will also be in English. There are some exceptions but they are relatively few.
"Edge of Tomorrow" was released in Germany with its original English title. The various home entertainment releases also bear the title in English, including the Steelbook.
If you check the thread for the German Steelbook release, you will find up to date imagery confirming that to be the case. Only the J-card will be in German. The Steelbook itself is in English.