George VI came up with Duke of Windsor because it referenced Windsor Castle and the name of the royal house, which he felt was appropriate for a former King. Edward liked it and it was settled. Interestingly, he did not create an Earldom or Viscountcy with the Dukedom of Windsor, as is usually the case for royal dukedoms.
I doubt Windsor will be re-created again unless there was another unusual breach in the line of succession.
I doubt Windsor will be re-created again unless there was another unusual breach in the line of succession.