Why would "this, this, and this" prove there is not a problem? I think everyone is jumping on a new feature to sell bikes, regardless of the braking performance increase or the heel strike consequences. The costs of this have been completely ignored in all of the "happy happy joy joy" and the security of the entire industry moving this way.
So who has actually ridden one of these for an appreciable distance? I am hoping that someone with size 45 shoes or greater and a short spindle like speedplay has can provide a report.
It proves that there isn't a problem because if there was the companies wouldn't bother going there. So much of what governs people's decisions in retail is perception. And being one of the first companies to switch over to disks will help with the brand's perception. However, being one of the first and then having everyone say you rushed a bike to market that wasn't ready because there wasn't heel clearance will have ten times the negative effect because now people won't want any of their bikes if there's a perception that they're under-engineered. And really, if you honestly think that stuff like this isn't massively over-tested before it goes to market, then you clearly have no idea how engineering and design works. Bringing a new model to market is ridiculously expensive. Carbon molds can cost well over 60k for something state of the art and that's for one mold for one size for a prototype. If you consider the total cost of developing and producing a new frame, and consider what would happen if the company got a reputation for not putting enough R&D time into their frames, then you'd realize that the prospect of a major manufacturer missing something as simple as heel clearance is frankly ridiculous.
My old team captain from the last team I raced for before I stopped racing has put on several 100+ mile days on his Crux Disk and he's got size 46 feet and rides with his heels in. Also, the founders of Volagi both are into double-centuries and have already tested both of their models at that sort of distance. If you want more than that I'm picking up my cross frame from Circle A on friday after they converted it to disks. I'll put some 175mm cranks on it (I usually ride 170) and take a picture of the heel clearance with my speedplays.