is probably a revision of EE – repetition of 
could have seemed superfluous. There is also a possibility, although, according to us, highly unlikely, that this indication was initially also in FE, in which Chopin, however, changed it to in the last stage of proofreading. After all, the composer's intention is not obvious here if we take into account the crescendi filling the following 6 bars. The orchestral voices also do not dissipate our doubts, since the cellos and double basses are provided with , yet violins and violas – with 
(the remaining voices are devoid of dynamic markings here).
Compare the passage in the sources»
category imprint: Differences between sources
issues: EE revisions, fz – f
notation: Verbal indications