The right thing to do. He needs to be replaced by a woman, and to Ariana's point they need several on the board. Plenty of work required to change the toxic culture at Uber.
FTFY: He needs to be replaced by a more qualified individual. It doesn't matter what gender they identify as.
Given the politics of the situation, reasonable people might hear in this: "A woman should not be hired for this role."
Imagine the optics of replacing a sexist old man with another sexist old man. Worth the risk to shareholder value?