AMS: "They had to right to grant or revoke whatever they wanted."
Only within the terms of existing agreements. There would be no point in having these sorts of agreements if you could just nullify them by "selling" something to another company and buying it back again the next day.
"Pace sold what they owned to Castle. Therefore whatever rights *Pace* had then Castle had. Whatever obligations ROL had to Pace they *then* had to Castle once Castle replaced Pace."
Yes, but also, whatever *obligations* Pace had then Castle had. Whatever rights ROL had stayed with ROL.