If you’re worried about whether it’s a good idea to stick with the Nexus 5, especially given its age, you shouldn’t be. Google couldn’t stop developers from pushing the newest Android systems for the device, and neither could Cyanogen.
Folks were worried when the company responsible for CyanogenMod (CM) – the main base from which custom ROMs are developed for Android devices – recently pulled the plug on the project, and that’s understandable.
The demise of CyanogenMod means that there’s no longer a place to host all the CM builds for the hundreds of Android devices out there, besides losing the resources needed to continually run their nightly updates.
But while really unpopular devices would probably lose custom ROM support from CM’s direct replacement Lineage OS, which is starting from scratch, Nexus users need not fret.
Along with the Nexus 5X and 6P, the Nexus 5 is supported by Lineage OS for Android 7.1 Nougat; except that instead of being called CM14.1, the unofficial build is now rebranded as Lineage OS 14.1. Whether or not it would be updated nightly or weekly is another question.
Sadly, the Nexus 4 and Nexus 6 aren’t listed for Lineage OS 14.1, at least not yet. You can check out the list of devices supported along with their download links here.