2017: "'Anemic' iPhone 8 demand drags Apple shares lower", https://www.reuters.com/article/us-apple-iphone/anemic-iphon...
2016: "Apple may be cutting iPhone 7 orders as demand falls", https://www.cultofmac.com/456431/apple-may-cutting-iphone-7-...
2015: "Apple stock slides on claims of slashed iPhone component orders, weak iPhone 6s demand", https://appleinsider.com/articles/15/12/01/apple-stock-slide...
Note that there were articles in those years also suggesting high demand. My point being that articles suggesting soft demand happen every year. Except 2014 when the iPhone 6 came out. Everyone was in total agreement then that demand was insane (and that quarter proved to be very hot indeed for Apple).
My point is that we won't truly know what demand looked like for the new iPhones until late January when Apple announces earnings.