I can't recall where I had heard it, I think was on the radio, but maybe they amended it, or it was something they were planning and haven't yet released. But the new restrictions they have in place today https://www.bay939.com.au/news/local-news/115468-borders-closed-overseas-travel-banned banning outwards travel to Australians, is more restrictive too than NZs, we don't appear to have yet banned it.
I can see all the countries where there are restrictions at https://www.nytimes.com/article/coronavirus-travel-restrictions.html?auth=login-google
UK doesn't seem to have much in place yet, nor Irleand, even though Ireland have closed schools.
You heard what you wanted to hear. Governments are being very careful and they aren't releasing their planning for this reason. Please don't post things like this without attributing them. This is exactly what starts panic buying and all sorts of crazy behaviour.
There will be no real panic buying. But for sure - expect a higher initial demand when people prepare themself for precaution-self-quarantine when asked not to leave home for that period of time. Or organize a dedicated delivery service with no contact by community or neigborhood.