The renowned Digital Chat Station shared an interesting report about upcoming Sony sensor that's being handed over to manufacturers for testing. Some speculate it's the rumored Exmor IMX800 destined for the Xiaomi 12 Ultra.
And it seems to be in line with the stories so far - 50MP, 1/1.1" in size, making it the biggest in the industry and just edging Samsung's 50MP 1/1.12" GN2 used in the Xiaomi 11 Ultra. The Xiaomi 12 Ultra's cameras will retain the 50MP, 48MP and 48MP resolutions, but they might still bring a hardware upgrade.
Source (in Chinese)