So who's going to be doing the harvesting, transport and sales while there's a war raging, the infrastructure has collapsed and people can't get money from the bank? They need more than bread, things like vegetables and meat, which all have to be grown, harvested, processed and distributed for sale. I know Ukraine is a bread bowl in normal years, and has a good climate for farming, but I somehow expect those projected figures were written before the war started.
After only a week or so of war we are hearing of severe shortages in the shops, and the places people live are being blown apart, cooker and all. Women are leaving in their thousands but the men and women who are staying to fight must be fed. An Army fights on its stomach and Putin will be trying to keep his supply lines open, as will the Ukrainian Army. It's how things happen in war and those women and children who don't get out who want to are very likely to find food hard to source.