Disney is not the only company said to have done this.
Los Angeles DWP as well has been reported to have done this.
It seems illegal and not compliant with H1B policy.
I am wondering why class action lawyers are not involved.
Because Disney did not fire the employees and replace them with H-1Bs. Disney fired the employees and outsourced their IT functions to an independent vendor...who then hired a bunch of H-1Bs. The first would have been illegal, the second is looked upon as a "sound business decision that maximizes shareholder wealth."
At the end of the day one has to wonder just how good that information turnover was. If I were in that position I think there are a lot of things I would forget to mention to my replacement. Or some mistakes I would include by accident.