There's been occasional talk of implementing something like this on the Git ML & devloper summits (and I've probably been the most excited about it), but for now this is deliberate and symlinking a tracked file to .git/config is a big exploit vector, you're basically giving everyone who's got access to the repository shell access on your computer.
That's because some configuration will allow you to execute arbitrary commands on the user's computer (aliases, but also various ..cmd config, etc.). Then there's other config that's also dangerous, but short of arbitrary code execution.
So, if git ever does start supporting a "tracked config" it would involve being very careful about the security implications. The approach I've advocated for is similar to how Emacs handles this, i.e. to have the user whitelist certain configuration keys/value types as "safe").
But for now it's not supported at all, one workaround for what you may be trying to do is to do path-based includes. I.e. if the reason you're setting the user and/or E-Mail is e.g. for a personal or work configuration, then you could clone those projects in ~/git/personal or ~/git/work, and have your ~/.gitconfig set the configuration for those accordingly.
