I think it's clear between 8K in DSLR cameras and this week's pro cinema RF mount release that the new RF glass is designed for much higher resolution sensors. Not sure if that makes EF worth less or more. Look at Canon's K35's right now, they're hot to trot with film makers for the added softness they bring.
I'm excited by this body. Past dual CF express cards, which seems a given if in second half of next year, I genuinely can't call what more you might need on top of the R5. 45MPx at 20FPS is crazy already. What's next?