Google just released the Android N developer preview for the Nexus 6, Nexus 5X, Nexus 6P, Nexus 9, Nexus Player, and Pixel C. The LG Nexus 5 is missing from the list, as it's quite dated now. However, as TheBleg points out, Nexus 5 owners could be in for a surprise, as Google is testing Android N for the device.
As evident from the Google Git repository for the Android N preview, the Nexus 5 (hammerhead) is tagged in its code dating from yesterday.
The company hasn't made official statement regarding the phone just yet, but this is definitely proof that the Nexus 5 could be in the basket of devices to receive the latest Android flavor.
Nexus 5 was still for sale on Google's store in March 2015. That's slightly over a year ago. It's not that old. It would be an inequity not to support N5 on Android N.
Please give Nexus 5 Android N
Nexus 5 will be excellent in Android N developer preview.