Quote:

Suggested documentation of the value in the wiki:
expected arrival/departure times at later operation or control points for a train during the journey

Would this imply, that scope="expected" times for a certain train may only be exchanged, once that train is actually under way? Strictly speaking, this would not cover the entire use case as described in the original post: Additional delays due to additional train crossings or crossings with delayed trains may be known and communicated before the affected train actually begins its trip.

I would rather suggest to link scope="expected" to the data source, which would be a forecast based on realtime data.