They do. Every patch release contains release notes and security notes disclosing what vulnerabilities have been identified and patched. This is industry standard practice, because this is a regular occurrence on all software platforms.

It’s not big news when it happens all the time.

What is big news, that’s gotten lost in all the noise, is that Google (through it’s crawling of the web) has been able to identify that some websites were (are) indiscriminately jailbreaking iPhones for the purposes of stealing user data.

This is the kind of thing that is routine on Windows, is likely to be routine on Android (given how many unpatchable devices are in use) but wasn’t considered to be routine on iOS.

The takeaway from all this is simple: if you’re not fully patched, you’re at significant risk. It doesn’t matter which platform you use.