But you don’t hear “Delays on the Overground”. What you *actually* hear is “Delays on the Overground between X and Y”.
This is no different to hearing about delays on, for example, the Metropolitan Line, when it might just be one small part like Watford that’s actually affected.
Actually, you *do* hear "Delays on the Overground".
Despite living in the east midlands, I get the London local news on the BBC news channel, and the delays dashboard provided for TfL (which is presumably based on information provided by TfL) has all the tube lines listed individually, but the entire overground lumped together; and the commentary by the newsreader seems to reflect this.
I'm pretty sure this will change to the individual named lines in the same way as the tube, and so become more informative.
Edit: The BBC status board seems to reflect the
TfL status board here which has the Overground lumped together. I would expect this to change, although everything may be delayed due to the TfL cyber attack a few weeks ago which I believe they are still recovering from.
I can see the current status board allows you to drill down for more details when there is an issue, but having the lines split out at the top level should avoid having to do this pointlessly when "your line" is not affected.