You can tell that the media doesn't want to report on this. They don't bother telling people the full impact of this latest gaffe. Because of the obscene complexities of the US tax code, a great many of those filers paid a tax preparer. Now they have to pay again (why should the preparer correct them for free? Wasn't his fault). Worse, some companies give out loans based on the expected refund. Now they are wrong. Finally, I have prepared state taxes in four states. They are all based on the adjusted gross income as shown on your federal taxes, and some states give credit based on federal taxes paid. I suspect most all states do they same thing. Those returns must now be amended as well.
Simply saying the taxpayer will have to file an amended return glosses over the time, trouble, and expenses filers must now endure.