The OPPO Reno3 5G showed up on TENAA today with some preliminary specs. The Reno3 will indeed support 5G thanks to the MediaTek MT6885 powering the phone. Other specifications closely match the Reno3 Pro 5G.
https://www.notebookcheck.net/OPPO-Reno3-5G-appears-on-TENAA-listing-preliminary-specs.447191.0.html