It may be different for different languages. There can't really be an authoritative answer because there is no authoritative entity defining what is right and wrong for a language like English. And it may change over time.
Basically, the idea is that the language should not rely on assumptions about the gender. The problems are in the details as far as I can see. Is mankind (giant leap for) still considered gender neutral? It once was.
Is he/she really outdated everywhere? WikipediaWikipedia still lists it under gender neutral language. What about he/she/they then?
I guess when in doubt it comes down to either avoid pronouns altogether or use they, especially when talking about the Stack Exchanges approved version of gender neutral language. The FAQ should simply say so.