This is an FYI about the operation of posts and the various feeds WordPress produces.
Posts can come and go. You can save a post without publishing it, and you can publish the post with a few options (comments enable/disable, password to view post, mark it private so only you see it, even change the date to make the post appear later on) Deleting a post after it is published (either outright deletion or marking it back to draft) can make a post go away when viewing the site, or the archives.
The feeds (check the bottom of the page, there is one for posts and one for comments) have a slightly different behavior. Yes, the feed will be updated with the deletion of a post. It will not store a post after it has been removed from published status. I’m also pretty sure that ‘private’ posts don’t show up in any feed.
However, a feed gets read by a program and stored for future reading. The idea is great, in that you can read posts via a feed at your lesuire without the trouble of going to the source site. Quite a few people I know subscribe to more blogs via feeds than I read in a week and they catch up on the feeds when they have no internet connection. There’s the thing: the software that reads the feeds stores it seperately.
End point being that once a post is made, published, and in a feed reader you can’t make that post totally disappear everywhere. There have been a few posts here that were later deleted that I have copies of in my feed reader.
Just something to keep in mind. You can take a post out to prevent future readers from seeing it, but that doesn’t mean it goes away for everyone.