I agree, just wanted to call out that in a few years you'll need (well want) to upgrade or look at a way to keep your dev machines safe from external threats. I'm guessing it'd actually be when you need new hardware to run the OS, it'll be a challenge to find older CPUs and motherboards.
Yes you're correct it's not "tombstoned", but it is EOL for consumers from Microsoft. They're pushing small security updates until 2020 and then it'll be like XP where tons of people run it but it never gets patched.
It's not ideal that the latest Intel CPUs (and AMD Ryzen CPUs) dont support anything prior to Windows 10. It's tough to tell people they have to run W10 on their latest PC build because the drivers dont exist for previous OS'.