"Disabling the new functionality" refers to maintaing the old behavior of hiding images by default. This means that you're leaking nothing unless you explicitly

"Disabling the new functionality" refers to maintaing the old behavior of hiding images by default. This means that you're leaking nothing unless you explicitly decide to. This does not appear to disable the proxying, though, so you're still covered by these additional protections when you do explicitly show images.