I would highly recommended that you just switch to a rooted gingerbread ROM. You can get a rooted stock gingerbread rom, you will lose your current setup but you can easily back up your apps with titanium backup and restore them.
To more specifically answer your question, given the nature of unrevoked3 you may be able to keep your phone's security turned off during an upgrade, however if there's an upgrade to the bootloader that will no longer be the case.