Focusing on the word "Office" feels like a bit of red herring considering it's frequently used in other Microsoft Office replacements like LibreOffice or OpenOffice.

Something like "EuropaOffice" would have followed the historical pattern so it's specifically the lack of an additional qualifier word that's perhaps questionable, not the word "Office."

But it does look like it's always called "Office.EU" in branding so maybe that's enough?