Your quoted text says 'unless required to do so by law, regulation'. H1-Bs would legally require a visa transfer to switch employers, and the company can simpl

Your quoted text says 'unless required to do so by law, regulation'. H1-Bs would legally require a visa transfer to switch employers, and the company can simply choose to not sponsor or transfer that visa. Thus, the worker is not eligible to work for them. Here are 3 immigration attorneys explaining this in another way https://www.avvo.com/legal-answers/can-a-company-refuse-to-consider-h1b-employee-in-u-1650791.html https://www.avvo.com/legal-answers/can-a-company-refuse-to-c...