Operating system: Windows 10 Pro
Graphics card: GeForce 1050ti
Broken: 2.82 (broken in a different way), 2.83.14, 2.92, 2.93 beta, 3.0 alpha
Worked: 2.79b (important is working in 2.81)
When using an armature modifier and subdivision modifier on the same mesh you get the wrong normals. If the armature is applied to the mesh then the subdivision normals are correct. The problem with the armature and subdivision together only applies if the armature is posed.
This broke between good ba1e9ae4733a and bad da6929488a64, probably rB9516921c05bd: Overlay Engine: Refactor & Cleanup
I think that a bug has come into 2.82 a fix has been applied but it has broken it differently. So between 2.81 and 2.82 something broke, then a fix was put in that is still broken but in a different way. So 2.81 is the good version.
Create a mesh and create an armature on the mesh. Add a subdivision modifier. Make sure the armature has a pose. Show the normals.
The consequences will mean that the surfaces are wrong and the subsurface and general render will just look wrong.