It is likely that at least one of the next devices to be released by Oppo will be of the R17 line of phones. A Chinese certification may have given more weight to this rumor, and also indicates how the front panel of such phones will look. It will apparently include a display notch, albeit a minimal one.
https://www.notebookcheck.net/Two-new-Oppo-phones-just-got-3C-certification.320874.0.html