Makes sense. After all it’s a heavily compressed video stream severely optimized for low latency and supposed to work over low bandwidth cables and WiFi. It’s not for the pixel peeper.
An informed display enthusiast would not be judging a display based on highly compressed, real-time encoded and likely wirelessly delivered (and as such glitch-prone) source material.
2021 and the cart is still there... Even connected via thunderbolt cable ipad pro 2020 does not show option to enable p3 gamut. Colors in Final Cut Pro viewer look different from main display if you move the viewer to the sidecar. Total frustration and disappointment.