The version of AI suggests that Chopin initially heard a monophonic melody in these bars or that he at least wanted to include all audible motifs as part of one melodic line. Eventually, he rejected this idea, probably unwilling to blur the polyphony-like structure of these bars. The additions in FES prove that this scarce notation was not understandable to everyone.
Compare the passage in the sources »
category imprint: Differences between sources; Corrections & alterations
issues: Annotations in teaching copies, Annotations in FES
notation: Rhythm