[dctoedt]

> Well the singular use of "They" is actually pretty old

The cardinal rule of writing is Serve the Reader — Don't Make Him/Her Do Needless Work. In modern parlance, "they" is an unobjectionable shortcut when you don't know who the person is, but it's just confusing to readers when it's about a known person. I'd be fine with a coined, gender-neutral singular pronoun, analogous to how feminists coined "Ms." decades ago and it's now practically universal.