I kept myself spoiler free going in and was surprised to see the prequel actors for Bail Organa and Mon Mothma return. And also to show Vader's injuries to mirror what happened in Episode III.
I thought Disney's directive going forward was that the prequels were to not be contradicted, but also not acknowledged.
This has never, never been the case.
Pablo even said on Twitter that Rogue One would forever end the idea that Lucasfilm ignores the prequels. They are canon forever and they are just as important as the OT.