Nikon has filed a patent on the design of upcoming Nikon APS-C DX Z-mount mirrorless camera. This camera is rumored to be announced in the second half of 2019.
Canon Japan has filed a new patent on curved sensor for their cameras. Currently in development, using a magnetic system to deform the sensor.
Canon has just filed a new patent today talking about EF & EF-S adaptor for full frame mirrorless cameras. This is just a patent, there is no sign that Canon will making full frame mirrorless cameras yet, also the EOS M APS-C mirrorless cameras are only for Asia and Europe markets now.