Thanks again. As I said, I am clueless on the technical side of cell phones. I hardly use them. Though I am very good with desktop computers, parts, OSs.
From that page you linked to:
Many unlocked phones also have a carrier variant, or carrier-branded version, which has different software. These different carrier versions have separate software lifecycles with separate updates and separate rollout schedules. This is why updates may appear at different times for different versions of the same phone.
So you are saying Republic does its thing through its app, and not the Android updates. Got it. That is good to know. I need to read up on the Moto X4. It is already almost a year old. That means it only has a little over a year left of guaranteed software updates.
That is why I want to go cheap. Iphones get more years of updates. I may go that route, and buy a used iphone. It looks like a used iphone6s and a new Nokia 3.1 both get 2 years of updates.