The OPPO Reno5 smartphones has been around for about 6 months now; therefore, going by this line's usual release cycle, it might nearly be time for a 6 series launch. New leaks suggest that they are indeed in the works, and will debut with similar premium mid-range specs, although at least 1 variant might get a newer SoC.
https://www.notebookcheck.net/The-OPPO-Reno6-series-is-tipped-to-launch-with-the-new-Dimensity-1200-processor.530696.0.html