Gender neutral pronouns?

I came across this article today while scrolling through Twitter, and it is interesting timing as I recently attended a literary performance with Ivan Coyote. Interesting timing, I say, because Ivan openly writes (beautiful, beautiful stories) about their life experiences - including that Ivan is a trans-gendered male.

Going into the event, I had a limited basic understanding of "trans-people" and was confused by the use of pronouns: If an individual is born one gender, but identifies with the other, and accordingly, takes steps up to and including surgery to transform into the gender with which they identify, then why may such an individual employ gender neutral plural pronouns (i.e. they and their)? Is it that some trans-gendered individuals, such as Ivan, have had "top surgery," but not - for lack of better terminology - "bottom surgery," and therefore, are technically both genders?

I am still unclear on this issue of pronouns; regardless, I thought of this matter while reading the above-linked article when it stated that "the need for a gender neutral pronoun is evident." Indeed, Ivan stated, "We've been here," and so, then, has this need for "non-binary" gender pronouns. In order for such additions to be made to the English language, I think our societal gender constructs must (obviously) be disassembled in the process... How long before individuals like Ivan stop being "they" and start being the one person they are meant to be? This is an intriguing issue that appears to be gaining more traction, and I am interested to see how it - and our pronouns - develop.