The version of As, replaced then by the final edition of those motifs, resulted from corrections itself. Their traces in the form of crossings-out are almost invisible on the available photograph; however, a comparison with similarly looking corrections in b. 18-19 suggests that in both places Chopin began with similar ideas and then changed them in a similar manner.
The change of the long grace note to a short one was an arbitrary decision of Fontana, certainly contrary to the intention of Chopin, which is particularly confirmed by the Chopinesque entry in FED, difficult to interpret as a whole, but in terms of rhythm almost certainly tantamount to the addition in b. 19, which is perfectly clear.
Compare the passage in the sources »
category imprint: Graphic ambiguousness; Differences between sources; Corrections & alterations; Source & stylistic information
issues: Main-line changes, Fontana's revisions
notation: Pitch