A product page for the Sony IMX607 CMOS sensor for smartphones has surfaced on Weibo. It is described as a 38 megapixel (MP) Exmor RS module with "advanced noise reduction", a novel dual Bayer-and-white HDR coding array and ambient light detection. Therefore, it may have enhanced low-light detection performance.
https://www.notebookcheck.net/New-38MP-Sony-sensor-leaks-could-be-destined-for-Huawei-P30-series.376866.0.html
RGBW arrays looked washed out, but I'm still interested about this RGBW sensor.