Unfortunately, various Magix programs have exhibited problems of "missing translations" over the years; this is another one! It may get fixed if you raise a support ticket , via the Contact button in the footer of every page, but don't hold your breath!
One or two members of Magix staff do occasionally read and post here but this is, essentially, a user to user forum.
the entry in the sound pools should change to English after a short time. If it does not work, then check the language settings in Music Maker (file -> language -> ...).