Was Cortot right about Etude op. 10 no. 1?

Question

I was reading through Cortot's edition of Chopin's op. 10 no. 1 etude "Waterfall" (link) and on bar 25 (page 10) he gives this note:

referring to these bars:

I was shocked to see this because I have always thought this particular section sounded unresolved and out of place but just assumed I was mistaken. Apparently, however, if Cortot is to be believed, this section is only written this way because of piano limitations in Chopin's time and, had Chopin been able to, he would have written it the way Cortot does.

Is Cortot correct about this passage? The highest note indicated by Cortot is a G6. I have done some research and found that Chopin used an 82 key piano. This piano does in fact have a G6, which seems to contradict Cortot's claim.

This also raises another closely related question. In the second image above in the bass you can see that Cortot gives alternative notes (or is this something else?) in brackets for the D. He also does this in the very first bar:

I have never seen these alternatives in any other edition. Did Cortot give these alternatives because he believed that Chopin's piano did not contain such low notes? In fact an 82 key piano does in fact have such a low C (C1) as modern pianos. Should we be playing the first C octave in the piece, and the other octaves where a lower alternative is indicated, one octave lower than they are usually played?

Answer 1

Consolidating Lazy's correct comments to make this question answered. Lazy, if you want the points I'll happily delete this post after you post.

The highest note indicated by Cortot is a G7, not a G6. The highest note of the original is a G6. You also need to take time into account. Yes, after 1820 we see pianos going up to F7, G7, A7 or even higher (generally between 1810 and 1820 about an octave is added, so earlier pianos went to G6-C7. So if we consider this etude was written in 1830 (when Chopin was 20) it is not entirely unplausible that at the time this would have been a range only playable on the newest instruments of the time.

Also as this published sheet music was probably intended to be sold to people who might not have had access to the newest pianos of the time it is plausible that this range was deliberately not used.