FWIW, I know what my policy would be for handling prequel material in future films if I were emperor of Disney.
Prequel-specific things can be alluded to without a problem, but never anything that appears to strain or break continuity with the OT.
Having Bail Organa depicted by Jimmy Smitts makes all the sense in the world. Referencing Mustafar is fine too. You could even reference Mace Windu as a Jedi by that logic, not that you’d want to.
However, it wouldn’t be acceptable to reference Qui-Gon Jinn as being Obi-Wan’s master, the Republic collapsing a mere 20 years prior to ANH, or Padme dying in childbirth.

This approach, which seems 100% consistent with what they’ve done so far in TFA and RO, allows three groups of fans to be happy: those whom want to ignore the PT, those whom accept but don’t love the PT, and those whom like the PT.