Yes, it was.

Germans started using archaeological evidence to justify territorial claims in France as early as the Treaty of Versailles; the German archaeologist G Kossinna wrote a letter to the German delegation arguing that archaeology proved German claims to Alsace Lorraine. He wasn't listened to. But over the subsequent 20 years, his interpretation became more widely accepted (in Germany, and to a lesser extent other parts of Europe), and German archaeologists did use 'Germanic' archaeological evidence (which the French government had been passively sweeping under the rug for decades) to justify their right to the territory in the 40s. Strangely, Kossinna's methodology (and many of his conclusions) became even more widely accepted after the end of the war, being spread through English archaeology in the work of G Childe.

You can read more about it in H Härke, Archaeology, Ideology, and Society: The German experience, and B Effros, Uncovering the Germanic Past.

Of course, there was actually no meaningful relationship between the 'Franks' who took over Gaul in the fifth century and the modern nation state of Germany (see G Halsall, Barbarian Migrations, P. Geary, The Myth of Nations). The use of Kossinna's archaeological interpretations to justify Nazi land claims is one of many examples of how inaccurate historical/archaeological scholarship can have disastrous real-world implications.