Always good to know thy enemy, even if they happen to employ you.
Below explains WARN notices from a State Employment Bureau site. What this says to me is an employer the size of a TBTF bank with a multitude of locations has a lot of latitude to lay off a lot of people without filing WARN notices. You WFH'ers who produce at a plant of '1' ain't gonna get an advanced warning from your state labor office. Buckle up.
WARN Listings
The Worker Adjustment
Discontinue an operating unit of 50 or more workers;
Lay off 50 to 499 workers, and these layoffs constitute 33% of the total work force at a single employment site; or
Lay off 500 or more workers at a single employment site
Although some businesses are exempt from WARN, the law encourages all employers to give workers sufficient notice, to the extent possible.