I'm not sure you can conceal your email address in practice if you
contribute changes to Emacs (or to any other projects with a public
repository). That's because anyone could see your email address by
just walking the commit logs. And many projects, Emacs included, have
a special mailing list where each commit is automatically posted, with
all its information, so anyone accessing the archives of such a list
will also see the email addresses of the contributors, and crawlers
can pick them up.
Thus, I'm not sure why you should insist on obfuscating the email
address in just those patches, since it will be visible in other
places anyway.