(a) This chapter does not apply to persons interested in the estate of a decedent who died before January 1, 1987.
(b) Notwithstanding the repeal of former Article 4a (commencing with Section 970) of Chapter 15 of Division 3 of the Probate Code by Chapter 783 of the Statutes of 1986, the provisions of that former article remain applicable where the decedent died before January 1, 1987. No inference as to the applicable law in effect before January 1, 1987, shall be drawn from the enactment of this chapter.