I'm going to have to see a cite and quote with full context.
A person can confront someone without instigating a disturbance. A polite request to hold the noise down is not instigating a disturbance.
You are assuming best case scenerio. I am assuming worst. Once a "polite" request falls on deaf ears and the requestor attempts to assert themselves, this is where the trouble would begin. There is noting necessary to cite if as in your scenerio the person politely requests and then exits hastily.
Good luck in WI taking the "polite" request a step further while carrying if the situation goes south.
Doug provided the cite above. Once you go beyond the polite request you are being disorderly and you become the provoker as you possess no authority to order them to be quiet.
939.48 Self−defense and defense of others.
2) Provocation affects the privilege of self−defense as follows:
(a) A person who engages in unlawful conduct of a type likely
to provoke others to attack him or her and thereby does provoke
an attack is not entitled to claim the privilege of self−defense
against such attack, except when the attack which ensues is of a
type causing the person engaging in the unlawful conduct to reasonably
believe that he or she is in imminent danger of death or
great bodily harm.