From Canon USA 14 March 2020 Press release on R5, as mentioned in Jared Polin Youtube video dated 14 March 2020.
"The EOS R5 will record internal 8K video capture up to 29.97fps, using the full width of the image sensor and will feature Canon's revolutionary Dual
Pixel CMOS AF technology in all 8K recording modes."
That is what they say now.
Wait and see if Canon cripples R5 in some way in the final product.
Canon is famous for cripple hammer, i.e. to purposely disable some of the product's abilities which it was already capable of.
Cripple to protect some of the company's other incompetent products that will not sell, if this product was magnificent.
Cripple so as to leave room for R3 and R1 which will have better features and specifications and higher prices.
Price is the problem. If very expensive then ordinary people cannot afford.
Still, it is good for Canon to have supposed improvement in R5.
NASA scientists call this process of innovation at the leading edge of technology "pushing the envelope"