The BBC World Service was originally received on Short Wave. Some countries ran it as their news, i.e. from 8 am to 9 am and from 8 pm to 9 pm every day.
The style of the old BBC WS was to announce the headlines, then explain each news story in depth, and at completion, restate the headlines.
The BBC WS then became accessible on FM in various countries.
If one listened to the BBC World Service, (up until 2000) they would be fully informed.
They would get a bit of background on each story, facts, interviews, so that at the end, one was fully aware.
That is why the BBC World Service changed.