I see why they call them Retroshifts. Essentially, they are the same as the very first crude integration of shifters and brake levers. Shimano, Campy, and Sram have been refining that concept for close to 25 years now. Why go back a quarter century.

Only possible advantage I can see is the ability to run in friction mode, but when was the last time you had a derailleur issue that you couldn't fix with the turn of an inline barrel adjuster?

I suppose you could bend a hanger in a CX crash and this could keep you going. But if you're serious enough about CX that you need to keep racing after crashing, and fing up your derailleur, you probably have a second bike in the pit.