Airport lays off 100 workers

The airport has laid off 100 workers who would not accept a reduction in wages asked of them by their employer. They will be replaced by contractors.

As I understand employment law: if your employer lays you off, it’s usually because there isn’t enough work, either temporarily or permanently. If the employer immediately turns around and employs someone else to do your work, doesn’t that invalidate the stated reason for your layoff?