Isn’t this advice basically the same has it has been for years if not decades? Have a few days of food and any medication. Torches, candles etc.
Annoyingly power banks are out of stock here because of this and I need a new one as my old one turned into a spicy pillow recently. Still got 1 left but its nice for us to have 1 each. Still, it lasted like 10 years so that isn’t too bad.
I think you’re right - but it used to be background information/recommendation tucked away somewhere on a website about flood preparedness or something.
This sort of ‘went out’ as a thing they were saying to do, and of course was picked up by news and media and repeated.
There’s a lot of people thinking “I forgot about that and never did get round to getting those things” along with people hearing it for the first time.
Mix that with “if they’re saying it out loud and publicly, maybe it’s a bigger issue than we thought”.