No they are not linked.

The preview usually works, but this time while I was working on a long and complicated answer, I lost my work a couple of times, which I am not sure why. This was another reason which prompted me to post before the reply was quite perfect, and why I mentioned a "sandbox" area as I think it is called in Wikipedia, or some place were one can save a work, while it is being edited, without publishing it.

Sorry, the answer was quite long with many technical computations, which necessitated corrections or improvements, although almost all were quite small and incremental. I do wish there was a "minor edit" option or a "sand box" area so that the problem you mention would not arise. As it were, I first typed the answer in a LaTeX document, but many formatting features did not translate well into Mathoverflow platform, resulting in added edits.