Hmmm, is CloudFlare known for being a bad actor in terms of privacy?

Setting that aside, no matter what you pick, you’ll be exposing your IP address, from which your ISP and/or general location may be derived

If you don’t trust CloudFlare with that information then you basically cannot trust anyone else, so maybe you’d need to run your own service and ping that instead now that you’re in a situation where you can only trust yourself 🤷

The other issue that comes to mind is that you’re only testing reachability to one address, which means you could get a false negative where that address stops working but the rest of the internet is actually fine