Makes sense - Flash models are (mostly) distills of the frontier model capability.

If they were able to make flash 3.8 so good off of their 3.1 pro model, flash 4 will probably be really good. But ofc you'd want your pro model to be as strong as possible in coding so that flash can take all those gains and efficient-ize them.

The better frontier you have the better distill you have because traces are of higher quality.

It's why Opus 5.5 is a beast