Apple insider Ming-Chi Kuo has revealed that the 2020 iPhone will draw inspiration from the iPhone 4 with its squared off and flat design. The possibility rings true given the 2018 iPad Pro redesign also adopts a similar design approach to what Kuo suggests. Regardless, the 2020 will be certain to feature the first all-new iPhone design in three years.
https://www.notebookcheck.net/Apple-to-revert-to-iPhone-4-design-as-inspiration-for-2020-iPhone.435517.0.html