This article talks about language change and stages. However, it treats the first stage only as a mistake. It dose not account for people making deliberate changes and how those progress. Webster is the most famous example of the latter, but usually it happens when an influential person makes one or a cluster of several related changes, and spreads them. A current example is the rise of alternative pronouns. That list is not going to stay infinite forever, but in a period of high change like now, the frame is left off. Eventually it will contract back to normal size, and English will either drop gendered pronouns altogether in favor of a single one for all humans, or it will add a few new ones -- I'd bet on a nonspecific and a gender-variant pronoun.