Metadata information seems to not be available on import. A user has reported that this was working before but I was able to reproduce the issue in //UE4/Release-4.24 cl 11590370
I am currently listing this as not a regression, further testing may reveal this to be untrue.
In order to access metadata from datasmith scenes the following line must be included before attempting to access metadata:
Final script should look something like this:
The Datasmith scene is imported but Metadata is reported as an empty array.
Metadata information can be manipulated during import.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-102042 in the post.