Pharasmins absolutely should follow their doctrine and kill us. The Pact Worlds similarly should fulfill their obligations and treat the church of Pharasma as a terrorist organization to be suppressed and prosecuted as necessary.
Yes, Pharasma wants you to die at what she deems your appointed time. But so what? Do you worship her, did she provide you with anything in your life that you should respect her wishes? Listen instead to wise Urgathoa, who defied Pharasma and was rewarded by the multiverse itself with godhood.
Like the changes in core gods, core races, and relaxation of alignment mechanics generally, I think the change to undead is all to the good for having a fresh new setting. I'm glad the Starfinder team had the freedom to experiment and shake things up.