Ever since the EOS R5 hit the market, Canon has pushed ahead with vigor in the mirrorless market, and it looks like they have no intention of slowing down. In fact, the company seems to be planning a camera that will challenge Sony for the crown of resolution by quite a bit.
At the moment, the Sony a7R IV holds the crown for full frame resolution, sitting at a whopping 61 megapixels. However, that 61 megapixels may pale in comparison to what Canon has planned. Canon Rumors is reporting that the company plans to release a full frame RF mount camera with over 100 megapixels of resolution at some point in the first half of next year. Currently, if you want to get into triple-digit megapixel counts, you will need to jump into medium format, but for the many photographers already invested in the Canon ecosystem, the option to use their RF lenses to achieve ultra-high levels of resolution is sure to be appealing. While such levels of resolution could challenge some older adapted EF lenses, Canon's RF lenses have generally been fantastically sharp and will likely be able to handle the extreme demands. Canon has been pretty faithful to their DSLR model conventions, so such a camera would likely serve as the mirrorless counterpart to the 5DS and might share some similarities in function and form with the EOS R5. We'll see what 2023 brings!