I wouldn't take romanticized descriptions of Chopin's playing too seriously.
Well sh*t, I stand corrected.
There isn't one "correct" way of doing rubato. There are certainly a million "incorrect ways" it can be done, but once you really understand the expressive content of what you are playing, good rubato tends to happen quite naturally.
I agree, but offer a word of caution. Bad rubato can also happen "quite naturally", and is common early on and in pianists who never got out of the habit. Rubato is never a case of slowing down because things got a bit tricky, or speeding up because they got easier. If you can't play it in strict tempo, what you are doing probably isn't so much "rubato" as a poor excuse for sloppiness.