How do you reduce autonomy to sacredness? I think of sacredness as something that inheres in some single object of veneration towards which a group of people can genuflect, such as a family shrine, a flag, a saint, or (for the left) "the environment". I would also extend the notion of a "single object" to slightly more abstract things, such as a single holy text (which might exist in multiple copies) or a single ritual way of eating (which might be enacted on multiple occasions).

One way in which sacredness commonly manifests itself is through sacred boundaries that serve as strong Schelling points. In fact, I am convinced that any large-scale human social organization depends to a significant degree on Schelling points whose power and stability rests on the fact that the thought of their violation arouses strong moral intuitions of sacrilege. (Even though this might be non-obvious from their stated rationale.)

Take for example the ancient Roman pomerium, the boundary of the city of Rome that was explicitly held as sacred. In particular, bearing arms within the pomerium was considered as sacrilege, and this norm was taken very seriously during the Republican period. Of course, a norm like this can easily be given a practical rationale (preventing coups, assassinations, etc.), and it seems plausible that it indeed had a practical effect of this sort, contributing to the long-standing stability and competitive success of the republican institutions. However, it was in fact the sacredness aspect that gave the norm its power, since a consequentialist rationale for any norm can always be rationalized away, thus making it a weak Schelling point, easily pushed down a slippery slope. And indeed, when the reverence for this traditional norm of sacredness started fading in the late Republic (along with many others), it was a good sign that the Republic had indeed gone to the dogs, and soon the state was torn by constant civil wars between competing generals who had no problem finding justifications and support for their plans to conquer Rome and seize power by armed force.

Similarly, intuitions of sacrilege can be associated with non-physical boundaries. Take for example the modern norms against euthanasia, even in cases where it's voluntary and in fact strongly desired by the patient, and the alternative is nothing but a prolonged suffering. People are horrified by the thought of euthanasia because it violates the perceived sacredness of human life. And again, one can make a cogent Schelling point/slippery slope argument in favor of such norms, but this is not what gives them their power.

Now, it seems quite plausible to me that this is in fact a common state of affairs for all sorts of norms that deal with the prohibition of crossing certain boundaries. Not all such norms are based on sacredness intuitions, of course -- they can also rest on a basis of fairness, harm, liberty, or some mix of those -- but in that case, their violation causes different and lesser kinds of outrage, and it's also easy to convince people to make exceptions based on concerns for fairness, harm, or liberty. For example, the norms about private property rights seem to be typically in this category: their violation causes nothing similar to the visceral feelings of sacrilege, and it's easy to convince people that some violations and curtailing of property rights are OK if you can convince them that it reduces harm and increases fairness or liberty.

With this in mind, I think it should be reasonable to ask whether the liberal intuitions of personal (and particularly sexual) autonomy are in fact a sort of pomerium backed by moral intuitions of sacrilege triggered by the perceived violations of this autonomy. (Whether or not we end up agreeing on the answer to this question.)