The 
raising e
2 to e2 added in FE2 almost certainly indicates a change of concept by Chopin. The original sound of e2 is confirmed not only by A, but also by Morch – in the parts of 1st violin, oboe and clarinet; moreover, violas include e1 (e1 in the 2nd French horn part is certainly a mistake). It is striking that the change was not included in EE, which means that it was introduced in the last phase of proofreading FE2. Similarly in analogous bar 343.
Compare the passage in the sources »
category imprint: Differences between sources; Corrections & alterations
issues: Authentic corrections of FE
notation: Pitch