It means they now have 100% ownership instead of whatever legacy rights were there from their previous investment.

It actually could be pretty lucrative. Not only have they gotten VW out of the mix, but they can renegotiate the salaries and stock options again. The market for talent is very, very different now. And all of those old options that the Argo people took during their first n years? They're now worthless so the management doesn't have to share ownership with them either.

This could have been entirely driven by business considerations.

This is all possible. There is a comment here by someone who knows one of the rehires and their contract is better for the employee. One data point etc.