I am afraid this is not currently supported. Please search the Revit Idea Station for "api highlight linked element'. You will see several wish list entries related to this. Please study those and vote for the ones that are important for you.
Whenever you require new or enhanced functionality, the Revit Idea Station is the place to go.
Please search there for a corresponding wish list entry for the suggested functionality and add your comments to it, or create a new one, if none already exists:
https://forums.autodesk.com/t5/revit-ideas/idb-p/302
Tag it as an API wish:
https://forums.autodesk.com/t5/revit-ideas/idb-p/302/tab/most-recent/label-name/api
Ensure it gets as many votes as possible to underline its importance to you and the rest of the developer community.
The Revit Idea Station is currently one of the main driving input forces for Revit API enhancements.
The Revit development team look there. Your comment here in the discussion forum might be overlooked.
Thank you!