Is this the future of English pronouns? Ada Palmer’s Too Like the Lightning takes place in a world where he/she is as quaintly obsolete as thee/thou. From the book’s opening:
You will criticize me, reader, for writing in a style six hundred years removed from the events I describe, but you came to me for explanation of those days of transformation which left your world the world it is, and since it was the philosophy of the Eighteenth Century, heavy with optimism and ambition, whose abrupt revival birthed the recent revolution, so it is only in the language of the Enlightenment, rich with opinion and sentiment, that those days can be described. You must forgive me my ‘thee’s and ‘thou’s and ‘he’s and ‘she’s, my lack of modern words and modern objectivity. It will be hard at first, but whether you are my contemporary still awed by the new order, or an historian gazing back at my Twenty-Fifth Century as remotely as I gaze back on the Eighteenth, you will find yourself more fluent in the language of the past than you imagined; we all are.
Related: Ann Leckie’s Ancillary Justice, a novel which uses “she” as an unmarked gender pronoun, and Douglas R. Hofstadter’s A Person Paper on Purity in Language, a satirical essay that imagines what it would be like if we made racial distinctions in pronouns rather than gender distinctions.