I just don’t understand this confusion. There really isn’t been a question of whether or not they were moving to USB-C for at least 6 months. The only question was whether it would be thunder bolt or not, and it isn’t. The narrative was always that they’d keep lightning for 10 years and then move to something new, Schiller even called it “a modern connector for the next decade” when it was announced, and at the time it was better than anything else on the market.
Now USB-C is the standard and superior, and it’s cheaper to bring the iPhone in line with that standard than to keep lightning or develop a new port/connector. As soon as the iPads went USB-C it was a foregone conclusion that the iPhone would follow suit, and anyone who was paying attention should have known it would happen this year, 10 years after lightning was introduced as a 10 year plan.