The rules: successions opened after 17 August 2015.
This part refers to Article 83(1)[1] of the Regulation.
Article 83(1)[1] of the Regulation, states that this Regulation shall apply to the succession of persons who die on or after 17 August 2015.
It should therefore be deduced that for successions opened prior to 17 August 2015, national rules of conflict shall continue to apply in the Member States bound by the Regulation.