While I think if people want this, it should be added as an option, it’s definitely not a feature I’d use.
I’d actually prefer a slight refinement of the current hiding read post feature. Allow us to tap the little eye button to toggle between show read and don’t show read posts.
Edit: that icon disappears when switching to compact mode. Which I use because I don’t like the large images on some posts. It often leaves me with only two posts visible in my feed: