Sports are not outside the world, so it is natural that politics may affect it.
The protest of the American black athletes at Mexico 1968, the American boycott of USSR Olympic games in 1980, the Davies Cup boycott against Chile, are all famous examples.
In motorsports, I remember Schwantz wearing a Desert Storm helmet in 1991 - now, that was not exactly a pacifist espression but it was definitely world politics entering the GP track. So was the opposite pacifist helmet worn by Rossi in 2003.
So something of that kind could be used, why not, if any riders feel like it they may wear a particular helmet to gently remind the Chinese that the world is watching them, and not only for business opportunities. Or the winner might perhaps do something special in way of celebration. I do not see Dorna or FIM taking any official position on this issue.