Seems that was bogus, as it was a straight copy-paste from a Canon Rumors spec list (and I really doubt Canon would ever claim something like 'Better dynamic range than the EOS R3 and EOS R5' in a spec list). Current rumor is a 24 MP sensor with a faster readout speed than the R3, with an AF system that can detect horizontal lines. Plus the 'Action Priority AF' that Canon mentioned in the development announcement.