ChewyWeAreNotHome: This has been an issue since initial release in August 2016. You can search for more detailed discussions but the short answer is that for stand-alone GOG has to do some coding so it may take a business day or two in their time zone before the stand-alone installers are updated although there are also times when both online and stand-alone are updated at the same time plus a few times over the years that the stand-alone installers for some patches never were released.
GOG support provided that explanation in these forums back in the fall of 2016.
Yea, I've seen discussion on it over the years, but thought it was getting better. Thanks for the info.. much appreciated!