The key sentence is here.
This is just an article, not a profound research. I can blindly say AAPL will meet Tim Cook last quarterly foretasted figures.
There are plenty of forecast software they (CEO team) run using various products, regions and finally declare the forecast. IMO, CEOs team used to review those figures to actual results on daily, weekly and monthly basis. That is the main reason, they are put in insider (who knows company financials).
No big company, like AAPL, fails to meet the forecast unless economy tanks.
The brighter side for AAPL is tax reduction (Increased profit), changes in supply chain (increases profit) - there are (will be) supply chain changes happening re-routing shipments to get max benefit from US tax and tariff changes.