The previous snapshot added practically nothing, only fixed some bugs. More significant changes have been made this week, most notably with the tagging system being more extensive.
An improved tagging system will help you create custom maps and data packs. Now tags can be applied to any type present in registries: blocks, biomes, items, etc. Custom tags will be stored in the data packs folder. Detailed instructions for using the updated tagging system can be found on the official website. Several bugs have also been fixed. Version 1.18.2 can be expected as early as next week.