F/7.1 @ 400mm - why? We already have 100-400mm f/5.6 and a 100-500 f/7.1.
Is Canon becoming allergic to fast zooms?
In many cases, Canon isn’t just duplicating the EF line in the RF mount. With better sensors and AF, they don’t have the same limitations as the xD and EF line.
The RF 100–500 is a replacement for the EF 100-400. The RF 100-400 is likely a replacement for EF 70-300 with a 67mm filter, costs and weighs less than half as much as the EF 100-400, and won’t be white.
With the new generation of sensors, 7.1 appears to be the new 5.6 for low end zooms. And the RF800 has shown that f/11, f/16, and f/22 AF are also possible with DPAF.