I'm not uploading the directories of files, but the names of the listed directories in the JSON file are descriptive to give context with the source and approximate Bedrock release date or version. If there's no source, it's from a zip in the BAO discord around that date. Otherwise it's from a git repository linked from here, or the latest Bedrock or BDS internal data files. Most of vanilla features / feature rules listed here have files distributed in the latest Bedrock versions, but not all, even for features/rules that can be overridden. I don't know why they were taken out.
I haven't compared the files (yet) to eliminate duplicates. The point was mostly to make a lookup list of what vanilla files I could get my hands on. Some of them will be outdated or unable to be overridden or adapted of course, but still interesting. Any more vanilla feature files around?