What Disney did is perfectly legal. They fired people, and hired a third-party contractor to fill the positions for cheaper. That third party contractor was "unable" find Americans to fill the positions of "contracted IT worker" so used H1-B workers to fill roles at the contracting agency, not disney. They were then contracted out by the agency (who they officially work for) to do work at Disney.

It is incredibly shitty and absolutely against the spirit of the visas, but it's not against the letter of the law.