There must be some misunderstanding about re-licensing. That can only be done for code one has the copyright for. A CLA/CA assigns or grants copyright or grants

There must be some misunderstanding about re-licensing. That can only be done for code one has the copyright for. A CLA/CA assigns or grants copyright or grants the ability to perform actions on behalf of the copyright holder. So "that company" controls copyright and can relicense. Other parties cannot relicense because they don't control copyright. Depending on the license, a party without copyright may be able to create a derived work that incorporates the original. The derived work may have a different license as long as the incorporation satisfies the original license. This is what people normally think of as using open source licensed code, and it does not include re-licensing code.