There was a short-lived site that I was presented, back in 2015, that had a similar idea. A user's 'home' page was a simple 4x4 grid and in each of the cells you could add pretty much any kind of content you wanted. Long form posts (truncated, on the home page, but could be clicked through to read in full in a modal), images (or galleries), videos, embedded content, etc. You had full agency to change any of the 16 things at any time.
There was also a "feed" page which just showed any cells that had been updated by users you follow, which made the feed page pretty much like any other social media.
I found it kind of charming that you had this very limited number of things you could be "saying" at any one time. You couldn't represent yourself with your entire history, but you could be quite expressive with just 16 cells of freedom.
I don't remember the site, nor can I find anything that seems to be what I remember, now. For some reason, I have the idea that it was killed off in a wave of "ephemeral" apps failing. But I don't know why I think that, so /shrug.
In any case, I find your idea to be charming in a similar way. I do like the idea of ephemeral representations, as opposed to a historical ledger of your entire usage with a site. And I also like the idea of, essentially, controlling your "headline" to such an extent that there are no (or very few) other options for people if they want to engage with your content at all. It's like "This is what I'm interested in, today. Please talk about it with me.", with an implication of "I can't focus on stuff from last week, even if you're only discovering it today, because of my new post."
For me, at least, that's a reasonable offering that I hope gains some traction!