I've looked for something like this before too.. I dont think it exists. Sometimes companies will get notified by USPS that your mail was forwarded and automatically change your address in their records or at least remind you to do so. That's my experience.

At the same time, being a security-conscious nerd, I'm not sure I would want to give even revocable OAuth access to a third-party portal to go in and change addresses to many of my most sensitive accounts... not to mention the fact that most banks etc dont have public APIs even if someone were to want to build something like this.

Just my two cents.