I have this idea that the R3 will be able to track a specific subject, e.g. a dedicated person ('s face) like the bride on a wedding. This (from Canon USA) sounds a bit like it (last sentence):
Code:
The EOS R5 and R6 were only the beginning.
Using Deep Learning technology,
the upcoming EOS R3 will offer enhanced AF performance
and tracking capabilities, with even better face-, eye-,
head- and body-detection.
And, the EOS R3 will add a new type of subject recognition, for its AF system.