Although viewers find out in the This Is Us season 5 premiere that Laurel did not die in childbirth, it is still unknown whether or not she is alive in 2020, where she is, what she has been doing for the past 40 years, or if she He always looked for Randall.
One theory from This Is Us is that Laurel may have been sent to prison due to her drug use and therefore was unable to search for Randall until many years later, at which point it might have been impossible for her to find him.
In the This Is Us season 5 premiere, Laurel is aware of this targeted attack and mentions that she herself is battling heroin addiction. Later, Laurel tells William that her friends Erv and Grace were arrested.
Laurel could have been involved as well and that would have made her a bigger target for arrest. This also heralds Laurel’s possible future career as Randall’s activist and / or therapist on This Is Us.
Along the same lines as the theory that Laurel may have gone to jail, it is also possible that she was not incarcerated when police and CPS arrived at her apartment after being called by paramedics who resurrected her in This Is Us.
But since Rebecca visits William in This Is Us season 1, when Randall is still a newborn and Laurel, for various possible reasons, is no longer with William, Laurel was probably alone and maybe even cut off contact.