Huawei is already working on its next-gen flagship SoC. The chipset, expected to be the Kirin 1020, will power Huawei's next generation of premium phones, starting with the Mate 40 and Mate 40 Pro. It's apparently scheduled to enter mass production in August.
https://www.notebookcheck.net/5nm-Kirin-1020-set-to-enter-large-scale-delivery-in-August.457534.0.html