RE AI writing and slang, the particularities of the examples aren't so important. My point wasn't to comprehensively catalog of every instance where we're losing something by not having timestamps on textlog specifically. The point was that time -- even relative time if not timestamps -- can be used to understand a piece of content -- often they are even critical, which you get.

I like the idea of playing with granularity. I'll also suggest: one way to make timestamps available but less of a focus is to add friction. Require an extra click into a post metadata page that loads with a full page refresh. Any friction introduced reduces a feature's usage, and even as little as just adding an extra page refresh tends to be enough to reduce its usage by an order of magnitude or more. If you wanted to be particularly sadistic you could require the user download a pdf with that data lol