Thanks very much for picking this up, Bryan. The new topic is very clear and well-written. I have only a few minor non-technical suggestions.
In the new text in "When cardinality statistics go stale", I'd suggest changing "info" to "information" where it occurs, to be consistent. Also, at the end of the second new paragraph, "procedures" should be changed to "procedure", since you're advising them to run one or the other procedure, not both.
In the new topic, you might want to add an indexterm or two, just in case we are ever able to generate an index. Also, it seems polite for links to other topics to include the title of the topic in the link, just so that users know where exactly they are going. It's a matter of taste, though.