It makes no difference how long you've been with a company so yes, it's legal to lay off any and everyone without severance. The exceptions: a union agreement requiring severance, a personal contract calling for a severance. This is usually only for executives and ``key'' people.
In Georgia, employees are presumed to be "at-will," and their employment may be terminated for any reason, at any time, with or without cause, as long as the reason is not specifically prohibited by law. This presumption is codified at O.C.G.A. § 34-7-1.
Georgia an “At-Will” Employment State For example, in Georgia, an employer's decision to fire an employee may be considered wrongful if the decision is based on the employee's membership in a protected class, is based on a protected activity, or violates an employment contract promising job security.