Can an employer terminate an employee in WA State with "restructuring" as the cause (job is eliminated), and then post the same job for a better hourly wage 4 months later? What can the restructured out employee do?
Yes. The employer can hire and fire at will unless the employee has a contract with a guarantee of continued employment or unless the decision is made for prohibited reasons, such as age, sex, race, disability, etc. If you have evidence that one of those prohibited factors was a reason for the employer's decision, you can contact an attorney or file an administrative charge with the EEOC or Washington State Human Rights Commission.
If you think the termination was motivated by an impermissible, discriminatory reason, you must file your EEOC (or Washington State Human Rights Commission) charge of discrimination within 180 days of any alleged act of discrimination. Be aware of that time limitation.