3 ideas
If a virus can rewrite an organism's biology, then categories such as species, sex, and kinship stop being natural givens and become the current output of a process that can be changed. Reading bodies this way moves attention from what a creature is to what has most recently written it.
When the physical makeup of a population changes, the institutions built around the old bodies (family, labor, hierarchy, law) no longer fit and have to be renegotiated. Social structure follows from biological substrate, so remaking the substrate unsettles every arrangement that assumed it was fixed.
The Linker virus works as an external agent that decides who beings become, taking over the role usually given to heredity, culture, or choice. Placing authorship of the self outside the individual raises the question of whether an identity rewritten from outside still belongs to the person who carries it.