Yes, your guide is absolutely correct. To further add, if you wish to unarchive any of your posts, just go to that specific archived post that you want to put back on your profile, tap on the “…” on the top right of the post, and select “Show on Profile”. This will instantly unarchive the post. However, it’s important to note that the post will return to its original location in your profile, chronologically. So if you’re looking to unarchive a post from 2 years ago, it won’t appear as your latest post, but will instead appear as if it was posted 2 years ago.