According to the news, Canon will launch the EOS R1 full-frame camera in the second half of this year. Along with this, the camera will not only be a mirrorless version of EOS-1D X Mark III but an ‘upgraded version.’
The media also predicted that Canon EOS R1 can shoot 6K (6144 x 3160 pixels) video and is supposed to be furnished with at least a 3:2 ratio 21 million pixel image sensor, support for shooting 120 frames of video, and Global shutter function, It will also have a dynamic range of 120dB.
It is worth mentioning that it will use a newly designed global shutter full-frame image sensor to create Canon’s highest high-speed continuous shooting speed record. The autofocus system is also more powerful than EOS R5 and R6.
(Source)