Along those lines: people's handles could be more memorable but still random. Maybe something like the github repository name recommender. "Oh, great, another post from ice-badger-weasel-fox, I love those!"
Good call, I like it!
I would caution you not to go for the cutesy, "random" aesthetic that github does with their name generator. People may not wish to be addressed in that way.
They'll never know if they are, and if they do -- they'll never know by who.
If that's still a problem, I humbly suggest that those people might not be the right audience for a socnet that lets one post only once a day.
maybe ala heroku? whispering-glades-5487
Having zero directed interaction might be a problem, but seeing only 5 thoughts for 24 hours makes you think about those thoughts a lot more and gives you a lot of time to process and answer them. Maybe there are interesting answers to your thoughts and questions you will never know of.