Regression testing done in //UE4/Release-4.27.2 CL-18427296 and this issue DID NOT happen
I did a little halo testing and found that when importing the normal map texture in by itself or within an .fbx file the compression settings were correctly set to NormalMap. This only seems to happen when importing a usd file. I also tried importing a usdz file in addition to a usdc file.
Expected Results: Normal map's Compression Settings should be set to Normalmap
Actual Results: the Normal map texture compression settings is set to Default, breaks the shading in viewport
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-150027 in the post.