In California, person dies intestate, heir igns his interest but dies, is the ignment valid?

A woman dies intestate with no spouse (divorced), no children, predeceased parents. Upon her death she had four siblings all living (none predeceased). During probate, one sibling igns his interest in the estate to another sibling, but before everything is finalized, he dies. He has three children. Without the ignment, the three children would divide his share. Does the ignment hold, even though he is no longer a "surviving" sibling when the estate is distributed? In other words, will the sibling receive his share, or will his children?