The Apple iPhone 5 was released in 2012. Apple has provided those users with 5 years of updates (assuming September is when they will release the new iPhone and also update the major iOS version number).
5 years is a long time in the mobile handset business... I doubt too many people will be livid about anything.
Also new ones still listed for sale direct from Walmart it appears: https://www.walmart.com/ip/Apple-iPhone-5C-8GB-AT-T-Locked/4...
If you purchased a new device and in less than a year support is dropped, yeah you might be livid.
Yes, such a bad purchase, a far faster phone with a better camera, better wifi and cellular connectivity, a better camera, and perhaps most importantly, far, far better security.
If all this does is help encourage people to get onto Secure Enclave-equipped iOS devices, it's a winner.