What are the rules for resubmission of a hardware device for Windows Hardware Certification being forced?

We have a multi-function peripheral device, which presents mouse, trackpad (not PTP) and keyboards HIDs to the OS. We will obtain Windows Hardware Certification for the device, but I want to know under what circumstances we would have to recertify. Reading the documents implies that any change to hardware or firmware on the device could trigger a need for recertification, but that would potentially mean that a bug fix unrelated to the HIDs would force us to recertify. Is that the case?