In A (→FE,GC→GE1) there is not any 
lowering e to e
. In EE the signs were added, yet at the same time the flats lowering f to f on the last semiquaver were omitted (except for bar 75, in which both last semiquavers are provided with flats). The reviser of EE might have concluded that Chopin wrote the flats in A one note too far by mistake (they may have regarded the E-F passage occuring in the first half of each bar as a confirmation that they were right). The flats lowering e to e were also added in GE2 (→GE3).
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: EE revisions, Omission of current key accidentals, Inaccuracies in A
notation: Pitch