LOL. This is the first time I've heard of it so thanks for the laugh. Although I don't suppose that was your intention.
Personally, I think it's another one of those things that bear no real significance that is given WAY too much attention. Particularly annoying are artificial words like 'hu' or 'eir'. Sure, languages change and develop, but forcing things of this type but a specific group based on one ideology or another is not a natural process. While 'his' may have originally been gender neutral, this is not the COMMON meaning today. That's all that matters. That leaves us with a perfectly good 'their' for this very purpose. Just because someone (no matter what their profession is, and how well respected they are in their professional community see how nicely it works?) decides it isn't OK, doesn't mean squat for the general population of the native speakers of that language. This is not a matter of a law of nature that's just been discovered. I'll repeat that again: It means NOTHING.