The use of the 
time signature is surprising only in GE1, as FE did not use the 
indication in the Etudes – contrary to the manuscripts – even once, neither in Op. 25 nor in Op. 10 and in the Etude in F minor, Dbop. 36 No. 1 (cf. also the Impromptu in A
major, Op. 29). Anyways, the correctness and authenticity of the time signature is undeniable with respect to the compatible version of GC and EE.
The correct time signature returned in GE2 (→GE3).
Similarly in bar 104.
Compare the passage in the sources»
category imprint: Differences between sources
issues: Changes of metre, Inaccuracies in GE, Inaccuracies in FE, GE revisions, 4/4 or 2/2
notation: Rhythm