The IRS has also stated that they mostly audit low income and high income taxes. But typically make their own adjustments unless they suspect fraud. Especially with being under staffed they also stated that unless it's believed that you owe them a significant amount of money from taxes they tend to not worry about missing w2s other forms I'm not sure about. But a missing w2 from most will get amended by the person later and if not it usually means the IRS would owe you money after an audit anyway.
