The right side of a desktop interface is useful when it answers a real question. What is recent? Which topic is active? Where should I continue reading?
In Osbirds, that context belongs in Widgets. The Inspector can use Recent Posts, Categories, Tag Cloud, Search, Text, or compatible block Widgets. The theme supplies a quiet fallback when the area is empty, but the site owner remains able to replace it from the normal Widgets screen.
This is the classic WordPress promise expressed through a modern surface: the design is opinionated, while the content containers remain familiar.