In a nutshell, when updating previews and metadata for DNG's, the camera profile should be embedded. It appears that's the case but in both LR5, LR6 and ACR, while the profile IS embedded and CAN be selected from the list, it doesn't default to the embedded profile. The default is Adobe Standard. I see what appears to be this 'bug' on Mac OS.
A picture might help. The OP sent me his DNG. The profile is shown but not selected which I think is wrong: