Even with the triplet, it doesn't call for the funk that so many pianists take liberty at expressing. In fact, I don't think anyone who reads what is written would ever interpret it with such pizazz, especially considering what comes before it. I think somewhere along the timeline, some pianist played it that way and it just caught on with other pianists copying it.
When does it change to 2/4?It starts out in:C (mm 1-20)3/4 (mm 21-2)C (mm 23-4)3/4 (mm 25-6)C (mm 27-9)3/4 (mm 30-44)Anyway, that's the second version, KK IVa Nr. 16. The first version has no such notated meter changes.