Google Home got call support last year, but although we've been able to make use of the hardware's hands-free VoIP support since then, there were a few noteworthy omissions. One of them was touch-tone number entry support for things like navigating automated menu systems. That exclusion has been fixed, as you can now tell Google to "press" numbers during calls.
We were tipped off about the new feature earlier today, and in our own testing, it works. Navigating phone menus should now be backward compatible with older menu systems. (Many automated systems do support voice-based navigation, but not all of them.)
Google has even added this feature explicitly in its support documentation, though it also claims that it isn't currently supported.
Based on our tests, it looks like it's time to update that page, Google.