I doubt a court would take that very seriously.
I think your analysis is wrong. If you want to find out how wrong just go to some event where women are exposing their genitals, such as a performance of Hair, or a strip club and go ahead and touch them. I think the DA will take it very seriously.
I don't know why we're talking about something that probably never happened or it it did didn't involve Kavanaugh, but she alleges that the man came up to her and shoved his penis towards her or "thrust it in her face." That could be considered assault itself, as well as indecent exposure. She says she pushed him away, a somewhat natural reaction.
Thrusting can be construed assault even if you don't connect (which would make it battery). Even without the thrusting or shoving in her direction, if you are walking around naked in what was most likely not your room, you aren't likely to be successful if you bring an assault case because someone pushes you away.