You mean what happens when they reject self ownership? - I’m guessing they are in a performative contradiction? If they don’t have a right to control, or own themselves, then who does?
“It may well be asked why life should be an objective ultimate value, why man should opt for life (in duration and quality).(5) In reply, we may note that a proposition rises to the status of an axiom when he who denies it may be shown to be using it in the very course of the supposed refutation.(6) Now, any person participating in any sort of discussion, including one on values, is, by virtue of so participating, alive and affirming life. For if he were really opposed to life, he would have no business in such a discussion, indeed he would have no business continuing to be alive. Hence, the supposed opponent of life is really affirming it in the very process of his discussion, and hence the preservation and furtherance of one’s life takes on the stature of an incontestable axiom.” - ETOL
(5)On the value of life not depending on whether it is perceived as one of happiness, see Philippa R. Foot, Virtues and Vices (Berkeley: University of California Press, 1978), p. 41.
(6)Elsewhere, I have written: “if a man cannot affirm a proposition without employing its negation, he is not only caught in an inextricable self-contradiction; he is conceding to the negation the status of an axiom.” Rothbard, Individualism, p. 8. Also see R.P. Phillips, Modern Thomistic Philosophy (Westminster, Md.: Newman Bookshop, 1934-35), vol. 2, pp. 36-37.
And if they reject property rights? - Well then they would have no political ethical objections to when they get killed, assaulted, or have their property stolen.
And should they reject them so they can rob and steal from others, then they again could have no objections when the same is done to them - as they would thus be guilty of special pleading.