I do not agree with the comment above about the open source part (that is just plain old FUD), but disabling internet access wouldn't protect against transmitting metadata unless you never turned it on again - it could simply store the metadata locally and wait until it found internet.

I think the point the above is making is that you can turn off internet/tcp/http access at the application level, say like we do with Notifications.

Surely this could be a welcomed thing.

iPhones sold in China allow you to do this. When an app is run for the first time, you’re asked if you permit it to access the Internet.