There are an awful lot of reputable breeders who have decided that breeding to Sonny is acceptable. I know that Melissa has thought deeply about this. I guess we'll see.
Your 45% comment isn't necessarily accurate in other than a general sense. I've read the study that came up with that number, which is general statistical figure for puppies from two parents with ED -- not the case here, as both parents have good hips and elbows. To my knowledge, no one really knows the risks in any particular pairing, and how ED is passed on, and how much of it is environmental, and what the true rate is, as most pet dogs -- the vast majority from most litters -- never get tested or reported. As you correctly note, almost all of Sonny's siblings were sold to show homes. Who knows what the rate would be if all pet puppies were tested and reported? That's one of the self-acknowledged limitations of the study you cite.
Also, the Sonny sibling elbows all seem to be from the particular pairing of Ryder x Versace. When you look at the pairings of each of those dogs with others, you don't see the elbows (but again, you also don't see all the pups going to show homes and getting tested). And unfortunately, no one knows how that trait is passed on, or if there is a heightened risk in subsequent generations (beyond the generation of Ryder x Versace pups). In fact, not a single study has noted a second generation increase in ED from pups who passed OFA; and instead have noted in that generation the exact same 11% rate of reported ED. So, the only study on point concludes that pups of parents who both passed OFA hips (even if siblings did not) has the exact same chance of ED as found in the general population.
Of course, none of this is determinative. We all want a LOT more information on these things. Our lack of real knowledge is frustrating, and can lead to a lot of different opinions as we all try to tease out the truth and the real risks. Which, I suppose, is why breeders differ so much in their ideas of what is and is not a risky breeding.
And the reason I am aware of the Ryder issues and ED studies is because of a long conversation with Melissa about this, and how she evaluated the risk in this breeding. She is very open about this. I even contacted some of the owners of Sonny siblings that didn't pass elbows to see what the situation was, hoping I could learn more about this. One was due to an injury. Two others were asymptomatic grade 1 ED in one elbow (both the left). None of them were bred.
I will be interested in seeing how all the great many Sonny pups around the country test as they get old enough for OFA certs. If you go by the study conclusions, this Sonny x Roxy litter should have no greater incidence than the general population. But we shall see.