Google introduced a simple fingerprint scanner gesture on the Pixel and Pixel XL that allows you to “swipe” the scanner to access the notification shade. This was not brought to the Nexus 5X and 6P, though, despite being an Android 7.1 feature, and the devices uses the same fingerprint scanner hardware as the new Pixels. After some confusion, technical reasons were offered up for the lack of support for the feature – namely: the firmware version of the scanner on the old phones wasn’t capable of implementing it, but that a firmware update was seemingly possible – it seemed that Google could potentially add the feature to the 5X and 6P, but for one reason or another chosen not to.
Google: "We’re evaluating" a firmware update to 5X and 6P to add fingerprint scanner gestures was written by the awesome team at Android Police.