This is nice in that Apple acknowledges that iPhone 6s and iPhone 7 devices still exist and are used. I wish third party developers would read that memo and get with the program. The App Store is becoming a ghost town of "This app stopped supporting your icky old device" warning messages due to app developers abandoning these phones.
They got the memo... directly from Apple that drops fully functional phones with their SDK updates, only giving you tiny crumbs of security update once in a while
Apps don’t support devices, by and large. They support SDK versions. Targeting a 4 year old SDK means not using a fair chunk of new OS features, which translates to at least some lost sales and developer happiness.
I’m sympathetic with your point, truly, but I also get why devs would aim at newer OSes.