The Post Author block combines the display of the author name, avatar, bio, and 'byline'. It's an older block that is fairly prohibitive in terms of design expression due to all the pieces being locked in position.

Modern themes tend to make use of the newer Post Author Name, Avatar, and Post Author Biography blocks, combined with layout tools like Row and Stack to gain greater control over the display of this information.

To avoid users falling into the trap of using an outdated block it might be worth deprecating Post Author (IE not surfacing it in the block inserter(s)).

If the prescribed layout is deemed to be of value a core pattern could be included which is constructed from the aforementioned atomic blocks.