Unfortunately the kABI does not encompass every symbol exported by the kernel, there is a whitelist maintained in the kernel-abi-whitelists package and scripts

Unfortunately the kABI does not encompass every symbol exported by the kernel, there is a whitelist maintained in the kernel-abi-whitelists package and scripts to check conformance of a module to the whitelist. Symbols are only ever added throughout the lifecycle of a RHEL release, so anything that conforms to the 7.3 kABI will also work on 7.4 - but if the module uses a symbol NOT whitelisted in 7.3 there's no guarantee the 7.4 update won't break it. Not that it's much solace when your proprietary blob breaks, but Red Hat does make considerable effort to give vendors a stable target to build against - unfortunately not everyone fully validates conformance which results in the same old problems cropping up from time to time.