I named a project after these! https://www.kleroteria.org
I love the messages from each of the people selected as they come in - some very interesting long scripts, others a single line, but all have made me smile.
I was selected a wee while back, but haven't gotten around to writing as yet - will add it to my task list.
There's around 1k members right now. I stole the 10k catchphrase from The Listserve. Consider it aspirational!
Yes, people can be selected multiple times, but they must submit a post before they can be selected again.
No, I don't currently plan to release the posts. I might change that at some point but I'd want authors to opt in -- even though the license allows it without their consent I doubt everyone understands that.
edit: updated; thanks for the feedback!