So to be clear, anything other than a 4chan-like unmoderated chronological feed results in loss of section 230 protection?

Heck, even 4chan wouldn't qualify, because despite considerably looser content rules they still actually do perform moderation.

Most sites that accept user-generated-content are forced to do some level of moderation, lest they become a cesspit of one form or another (CSAM, threats, hate speech, exposing porn to underage users, stolen credit card sales, etc...)