Historically understood to be plural by you. Actual-historically, from 1375, not so much. https://public.oed.com/blog/a-brief-history-of-singular-they/ https:

Historically understood to be plural by you. Actual-historically, from 1375, not so much. https://public.oed.com/blog/a-brief-history-of-singular-they/ https://public.oed.com/blog/a-brief-history-of-singular-they...