We should not need an emergency defined to prepare for it. That's the whole point. It's being prepared for the unexpected.
I would say that the risk of the unexpected is currently higher than it has been in a long time, hence the advice, but it doesn't mean something will conclusively happen.
I would say the biggest risk ATM is a diesel and gas shortage. This has worldwide implications.
Some places worldwide are already facing rationing or blackouts. This has an impact on manufacturing and UK imports.
The biggest concern would be medication.
But more widely the entire global logistics network operates using diesel. Think trains, tractors and trucks. As well as cargo ships. This means transport, haulage and farming.
Even without a lack of supply prices are going through the roof and this will have an impact on everything.
In addition to this, next year will see high food prices. Fertiliser wasn't available or was too expensive for farmers around the world earlier this year and currently. So crops that are already in the ground or haven't been planted at all are going to have much lower yields. For parts of the world this will mean starvation and civil unrest. This is now an inevitability.
The UK is unlikely to run out of food, but it could skyrocket in price and there may be gaps on the shelves - because of lower crops and higher costs to get the crop to you and higher costs to process the crop.
Not to mention that the energy price cap is almost certainly going up 25% in January
Being prepared may not merely be about an incident.