The remaster was originally criticized for its "over-bright" lighting and odd-looking character faces compared to the original. This update (and those around it) adjusted the lighting systems and textures to make the skin tones and environments look more natural.
It addressed several crashes and "quality of life" bugs that players encountered during the American Revolution campaign, particularly on the PC version.
The at the end of your string likely refers to CODEX , a well-known group that releases digital backups and updates.