I'd favour the former example, you can then also have a symlink https://estalink.us/schemas/latest/rdm-schema.json which always points to the most recent version and the filename itself is always the same when downloaded, which is probably easier for software to manage (assuming the version is represented as a property within the JSON file too. I see it's currently in the id, it might be nice to have it duplicated as a clear semver field too, which doesn't require any fiddly parsing of the URL, although duplicating a value isn't great either.
I'd favour the former example, you can then also have a symlink https://estalink.us/schemas/latest/rdm-schema.json which always points to the most recent version and the filename itself is always the same when downloaded, which is probably easier for software to manage (assuming the version is represented as a property within the JSON file too. I see it's currently in the id, it might be nice to have it duplicated as a clear semver field too, which doesn't require any fiddly parsing of the URL, although duplicating a value isn't great either.