To make that happen smoothly, I've also implemented a revision and versioning system, allowing you to view the past revisions of all the posts in those books, and marking comments made against older versions of the post. I did this because a significant fraction of the discussion in the comments was referencing problems in the posts that are addressed in the latest versions, as well as wording that has been changed.
A post having past revisions is indicated by a small history-icon next to its date, which when clicked will allow you to select from all past versions of the post after it has been published. This is currently only available on desktop, the mobile version will follow soon.
We are planning to make the revision system available to everyone soon, which will allow you to uniquely link to any article in its current version, without having to worry that it will ever change. I hope to also make it so that you can get notifications to new major versions of posts that you are subscribed to. This is part of a broader effort to make posts on LessWrong longer-lived and have more of a wiki-feeling to them, and also to make it harder to accidentally delete your whole post with a wrong submission.