The download of this file occurs when AI features are active, but that the interesting part. AI features are active by default in the newest releases of Chrome. Realistically, this isnt completely new. People discovered the weights file last year, around five months ago , as of writing. Even when you delete the file manually, Chrome will redownload and reinstall it in a continuous cycle. To truly disable the feature and remove the file from storage for good, you must disable the Chrome flags...
