Has it ? You mean The
War Version 1, where there was 'Scud FM' using R4's FM network, the precursor to Radio 5 Mk 2, (what we have today)
I was more thinking about the BBC World Service which launched in 1932.
BBC World Service radio, has never been a rolling news station, at least not in the last three or four decades, it has on the hour news bulletins, but so does Radio 2, Capital, Heart FM, etc etc. That doesn't make them rolling news stations, any more than World Service Radio
You clearly don't listen to it very often.
Yes there are hourly bulletins, and there are also half-hourly headlines.
There is Newsday which is broadcast from 03:00 to 08:30 every day, World Update from 10:00 to 11:00, Outside Source from 11:00 to 12:00, and Newshour at both 14:00 and 21:00. Throw in five 30 minute editions of the Newsroom between 17:00 and 00:30.
That to me is not far off a rolling news service, given those programmes alone count for 12 hours of broadcasting.