The version with g3 (in b. 506) and g2 (in b. 508) would be possible but for a broader harmonic context, and especially the E minor key in force here since b. 495. Therefore, there is no doubt that Chopin omitted naturals and the version of GE is correct.
Compare the passage in the sources »
category imprint: Differences between sources
issues: Errors in FE, Errors in EE, GE revisions, Omission of current key accidentals, Errors of GC
notation: Pitch