Dammit... you and your reasonable posts are seriously cutting in to my memeing.
Under the RLA, WARN notices do not have to be sent to individual employees, and can instead be sent to the union leadership (if there is a bargaining unit). It still must include each employee's name and position that could be effected. There is a paragraph in the Federal law that allows individual state laws to be more restrictive. That is why employees based in some states get individual WARN letters. For example, our pilots didn't get individual letters because we only have one domicile in a state that doesn't require it, but our FAs have two domiciles, and the ones based in California got individual letters.