When your God can be killed by us silly goobers, maybe he wasn't so powerful in the first place.
But god is already dead. God remains dead. And we have killed him.
Though 'we' seems to be germans as the quote is by german philosopher Friedrich Nietzsche and even before Nietzsche, the earliest accounts of 'death of god' discussions seem to originate in german lutheran culture of the 17th century.
So since god is dead and transgender rights are some modern stuff, trans rights cannot have caused the death of god.