There are about 393 million firearms in the US. Conservatively, maybe 500k for those gun owners are looking for reloading components right now. That doesn't even include the record number of new gun owners looking for ammo. In addition, you are competing with resellers and gun shops who are buying inventory just to turn it around and resell it. When Powder Valley, Brownells, and Midway USA are selling pallets of primers within about 5 minutes of listing them while trying to keep their systems from crashing, its unrealistic to assume they are going to send you an email "heads up" in time. If you actually get the notification, its going to be after everything is sold.
If you want to purchase primers, they are available. If you are only looking for 100-1k of something, Cabelas always has something listed. If you are looking to buy 5k or more, you are going to have to spend time sitting in front of your computer.
I'm afraid this condition is going to will be with us for a while and depending on what happens in November, may never get back to normal.