This document is under near constant revision. Except where releases have very few changes, all HTML pages are uploaded afresh for every TB release as is the zip of all the images.
For minor typos, if time is pressing, just the affected HTML page will be uploaded. This means the 'last updated' time on the home page may not always be true, but it's a pragmatic trade-off. In the same vein, if the edit is to a note on an attribute, action code or export code, all of which content is stated 3 times (original and two aliases) at time only the original will be corrected in the HTML; the original's page is always the one in the full listing for that section.
To assist TBX-based users watching the version and build checkers, a full local export is done when feasible even if only a few affected pages are uploaded. In such circumstances this will include the RSS/Atom feeds, the zipped TBX and the index page (so the latter's updated time will be correct).