If there is any metadata included in an Item, it can be imported to Kentico.

You should add metadata fields to your Content Workflow Templates, just like any other fields which you want to be mapped and copied during the import process. All Metadata content should be captured in a separate tab.

If metadata content is independent of a specific language within a multilingual project, it should be mapped only once in any language-specific mapping. Otherwise, metadata fields should be mapped for every language independently of any other content.