Change from Vivace in Ap to Allegro in FE (→GE,EE) may have been related to the fact that the next etude, the Etude in E major, had originally Vivace as its tempo. The number difference in the metronome marking is not significant (144-138), yet the change of the used rhythmic value draws attention. It may have been related to the change of the time signature, although FEcor proves that the changes took place at different time:
Chopin would have had to introduce a possible change from 
into 
already in the autograph, as in FEcor there is already , on the other hand, the metronome tempo was added only during a subsequent proofreading. The authenticity of the time signature's change is, however, dubious.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: Errors in FE, Changes of metre, Errors in GE, Metronome tempos, Authentic corrections of FE
notation: Verbal indications