No. He's out because he works in a professional environment and knows that the statement that Mx is a universal title that can be used with anyone is untrue. In the vast majority of workplaces in the world, you'd get a weird look for calling somebody with an obvious gender identity Mx.

The source discredits itself by claiming Mx is some sort of conventional title

There is man,

there is woman,

and there is Klinefelter's.

(worth the karma hit)