There were several discussions on this, this one
and this one
come to mind.
It all seems to have started with the last one, when someone asked Waze to remove all JUNCTIONS that connect railroads with drivable roads, and Waze responded "sure, we're deleting all railroads!"
I think it's stupid. Railroads are an excellent reference point.
I see that sandjaja posted the first link I did, but that wasn't the original discussion. The second link I've included is the one that has the response from support saying they're deleting railroads.