The absence of the raising the top note of the mordent from a2 to a2 in the sources is almost certainly an inaccuracy in this context. Such imprecise notation of ornaments – grace notes, mordents, trills or turns – is a quite frequent phenomenon in Chopin's pieces, cf. e.g. the Nocturne in C minor, op. 27, no. 1, bar 75 or the Sonata in B minor, op. 35, the 2nd mov., bar 54.
Compare the passage in the sources »
category imprint: Interpretations within context
issues: Inaccuracies in FE, Omission of current key accidentals, Errors repeated in GE, Errors repeated in EE
notation: Ornaments