This has happened before with ammo and guns. And it will for certain happen again. Mostly after every big mass shooting, or political election that triggers anti gun fear. Parkland, Ft. Hood, Las Vegas, Sandy Hook, Pulse night club shooting, Obama's election... Twice. Just to name a few.
People refuse to plan, regardless of how many examples you give them that it's wise to do so. Look at Florida, along with the deep South every time there is a hurricane. They all run like Lemmings to strip the shelves of plywood, water, chain saws, generators, canned goods, and flashlight batteries. Then on the way home, wait in line for 4 hours to gas up their cars. Every time for every hurricane that comes along. You would think they would wise up by now. But they never do, and they never will. This is no different.