The OPPO Reno3 series has been teased again in even more detail by its OEM ahead of these phones' late December 2019 launch. This time, the company has let the base model's processor name slip. It seems this device will be powered by the heretofore-unannounced MediaTek 1000L chipset.
https://www.notebookcheck.net/The-OPPO-Reno3-will-be-powered-by-the-5G-MediaTek-1000L-SoC.447252.0.html