It would be a real threat to Austria, which was the second main rival to France after Britain.
Well, Austria has been correctly described as a nation of Slavs, Transylvanians, and Magyars with German-speaking Monarch at the top.
Yeah, the Austrian-Germans are obviously a minority in their own Empire, more so after the constitutional reform of 1920 that basically turned their Politics into Magyar vs Slav voting blocks. Sure, that kind of arrangement is kind of stable, even until now, but it's still kind of awkward.