I pulled open the standard as linked by cnvogel and expected to see what is in a sense the exact opposite... a list of all vaguely practical hand gestures, with the middle-finger merely one in a sea of gestures. While it is in the middle of some other more generic gestures, some of which definitely have obscene connotations in some cultures [1], it's less exhaustive than I've come to expect from Unicode. See also [2] which lists some cultural middle-finger equivalents, some of which show up in the Unicode list, or in the case of 1F594 ("peace") easily can if the icon designer is not careful. (In fact I think the Unicode sheet shows the obscene-in-the-UK variant.)

I sort of expected to be able to make a crack about it being a bit culturally imperialist not to include the middle finger just because the US considers it obscene, but instead it stands out more than I expected, so I can't.

[1]: https://en.wikipedia.org/wiki/A-ok#Negative_connotation

[2]: https://en.wikipedia.org/wiki/The_finger#Similar_gestures