You can create a custom update to remove older versions of Java should the update leave any behind, for instance, if you ever installed Java using the STATIC=1 option or if you're trying to remove Java 6 or 7 after installing 8. To do this, gather up the MSI product codes that you want to remove from systems, make the custom installer use MSIEXEC to remove them using the /x flag, fill out the update details, don't include and "update is installed" rules, and set the applicable systems to systems that have the versions you want to remove installed, but only if the latest one is already installed. (Hint: use an OR filled with the ones you want to remove nested in an AND that contains the OR and the latest version you want to keep).
If you don't include the "make sure the latest one is already installed", then it will simply uninstall the targeted versions of Java from the targeted computer.
If you don't include the "make sure the latest one is already installed", then it will simply uninstall the targeted versions of Java from the targeted computer.