In FE the oversight of the clearly written slur in A seems to be a mistake. However, taking into account the recitative and culminant character of this motif, one cannot exclude the deletion of the slur by Chopin in the proofreading of FE1. In GE and EE the slur was added probably after analogy with the previous bars.
Compare the passage in the sources »
category imprint: Differences between sources; Corrections & alterations
issues: Errors in FE, Authentic corrections of FE
notation: Slurs