This is really being driven by tandem OLED with blue phosphorescent (not fluorescent which is the current commercial design) layers, most likely from Universal Display Corp. The blue phosphorescent OLEDs have (note red/green are already) longer lifetime and and efficiency, but they aren't the deep blue you need for 3 primary displays.

Samsung and LG which both demoed ultra-wide color gamut/volume displays at SID 2026, but also CSOT/TCL. This allows even greater than BT.2020 coverage (APEX pixel is 131%!) or trade off for lifetime with higher brightness/efficiency.

The original 4 color LCDs (like RGBY/RGBW) was driven by a long ago need for brightness and resolution with fewer subpixels (see Samsung's Pentile RGBG arrangement). This both solves a different problem and the technology is being driven by a different development (and marketing).

https://en.ubiresearchnet.com/sid-2026-bt2020-oled-display-t...