I’m sure this is due to the fact that Apple have only just stopped selling the iPad Mini 4 this year, and it would be pretty bad for them to suddenly stop supporting it with software upgrades. But the iPhone 6 has the same A8 processor. And yet it won’t get an iOS 13 upgrade. I’m guessing that, because, what was iPhone OS > iOS has now diverged to iOS and iPad OS, that the same processor subset isn’t in the plan for older iPhones. Okay, I’ve got both an iPhone 6 and iPad Mini 4 and they’re both what I use on a daily basis. Just wish there was maybe an update for the iPhone 6.