True, but most (all?) NPM packages use free software licenses. If you use such a license you've already granted an irrevocable license to everyone. NPM doesn't

True, but most (all?) NPM packages use free software licenses. If you use such a license you've already granted an irrevocable license to everyone. NPM doesn't need your explicit permission to upload the package to begin with. If you want to be selective about who can freely distribute your code, then you shouldn't be using a free software license.