I had no idea who Nathan Marz was. When I saw the title, I assumed "Leaving Twitter" was implying discontinuing usage of Twitter from an outsider's perspective, not an employee parting ways with the company. The original title is completely unambiguous.

AFAIK all of the mods are YC insiders, so they'd know Marz by name.

If it is as you imply, that's a pretty serious Theory of Mind failure on their part.

Agreed, and more importantly, thank you for introducing me to the term "theory of mind." It seems a nice way to succinctly refer to the notion of understanding the perspective and level of familiarity of others.